At least on SRC680m204 unxsoli4.pro under Gnome, calling new javax.swing.JTree()
in Java code within soffice.bin causes SEGV.  It succeeds if
program/libjavaplug_gtk680si.so is removed.  It fails with Java 1.5.0_07 and
1.6.0, but succeeds with Java 1.4.2_11 (those were the versions I had at hand).

To reproduce, deploy the attached JTreeComponent.uno.jar into OOo
(program/unopkg add <path-to>/JTreeComponent.uno.jar), create a Basic macro

sub main
  dim s() as string
  createunoservice("jtreecomponent").run(s)
end sub

and execute it.  If successful, it prints the two lines

--- before new JTree
--- after new JTree

to stderr.  Below is dbx output for an unsuccessful run:

--- before new JTree
Reading libawt.so
Reading libmlib_image.so
Reading libmawt.so
Reading libXm.so.4
Reading libXp.so.1
Reading libXt.so.4
Reading libXtst.so.1
Reading libfontmanager.so
Reading xomCTL.so.2
Reading liblayout.so.1
Reading umle.layout.so.1
Reading libnet.so
Reading libnio.so
Reading libsendfile.so.1
t@1 (l@1) signal SEGV (access to address exceeded protections) in (unknown) at
0xef60fc59
0xef60fc59:     lock cmpxchgl  %edx,(%ecx)
(dbx) where
current thread: t@1
  [1] 0xef60fc59(0x0, 0x8044e1c, 0xd67a6e68, 0x8044e50, 0xd70836e0, 0x0), at
0xef60fc59
  [2] 0xef6029a4(0x0, 0x0, 0x0, 0xce617078, 0x1, 0xce616f68), at 0xef6029a4
  [3] 0xef6029a4(0x0, 0xce616f68, 0x8044e8c, 0xd66a48b9, 0x8044eb0, 0xd6ef7d00),
at 0xef6029a4
  [4] 0xef6029a4(0xce616f68, 0x8044eb4, 0xd66a41c0, 0x8044ee8, 0xd6ef7d00, 0x0),
at 0xef6029a4
  [5] 0xef602a7b(0x0, 0x0, 0xceb5b310, 0xceb6b170, 0xce616f68, 0xce616f68), at
0xef602a7b
  [6] 0xef602a7b(0x0, 0x0, 0x0, 0x1, 0x0, 0x0), at 0xef602a7b
  [7] 0xef6029a4(0x0, 0xceb54558, 0x0, 0xceb6b170, 0x9, 0xceb45ab8), at 0xef6029a4
  [8] 0xef6029a4(0x0, 0x0, 0xd6eed108, 0x9, 0xceb3a2a8, 0x8044fc4), at 0xef6029a4
  [9] 0xef602a7b(0x0, 0x0, 0x9, 0xceb3a2a8, 0x8044ff8, 0xd67a5d98), at 0xef602a7b
  [10] 0xef6029a4(0x0, 0x9, 0xce680278, 0xce6802a8, 0x804502c, 0xd67a5e4f), at
0xef6029a4
  [11] 0xef6029a4(0x9, 0xce6802a8, 0xce680278, 0x804505c, 0xd66fc76c,
0x8045088), at 0xef6029a4
  [12] 0xef6029a4(0x0, 0xceb3a2a8, 0xce6802d8, 0x804508c, 0xd66fc6fe,
0x80450b8), at 0xef6029a4
  [13] 0xef602a7b(0xce680320, 0xceb41660, 0xce6802d8, 0x80450bc, 0xd66fc685,
0x80450e4), at 0xef602a7b
  [14] 0xef602a7b(0xceb41660, 0xce6802d8, 0xce6802d8, 0x80450ec, 0xd66b2bc4,
0x804511c), at 0xef602a7b
  [15] 0xef602a7b(0x0, 0x0, 0xceb41660, 0xceb608b8, 0x8045120, 0xd66bd66a), at
0xef602a7b
  [16] 0xef6029a4(0xceb41660, 0xceb608b8, 0x804514c, 0xd6672d60, 0x8045184,
0xd6eb6170), at 0xef6029a4
  [17] 0xef6029a4(0x0, 0x0, 0x0, 0x0, 0xceb41660, 0xce680330), at 0xef6029a4
  [18] 0xef6029a4(0x0, 0x0, 0x0, 0xceb41660, 0xce680330, 0x80451c0), at 0xef6029a4
  [19] 0xef6029a4(0x0, 0x0, 0x0, 0x0, 0x0, 0x0), at 0xef6029a4
  [20] 0xef6029a4(0x0, 0xce680330, 0x804524c, 0xd688d9e9, 0x8045274,
0xd720b5c0), at 0xef6029a4
  [21] 0xef6029a4(0x0, 0xce680330, 0x8045278, 0xd68a151a, 0x80452b8,
0xd722b3c8), at 0xef6029a4
  [22] 0xef6029a4(0x0, 0xce680330, 0xce680510, 0x0, 0x0, 0x0), at 0xef6029a4
  [23] 0xef6029a4(0xce680500, 0xce680510, 0x0, 0x0, 0x0, 0xceb41748), at 0xef6029a4
  [24] 0xef6029a4(0x0, 0x0, 0xce680560, 0x804532c, 0xd68a09b9, 0x804535c), at
0xef6029a4
  [25] 0xef602a7b(0x0, 0xceb41748, 0x0, 0xce680528, 0x8045360, 0xd689fc6f), at
0xef602a7b
  [26] 0xef602a7b(0xceb37a88, 0xce680528, 0x804538c, 0xd68980b3, 0x80453b4,
0xd7220cb0), at 0xef602a7b
  [27] 0xef602a7b(0xceb37a88, 0xceb60a00, 0x80453b8, 0xd689e439, 0x80453ec,
0xd7226f78), at 0xef602a7b
  [28] 0xef602a7b(0x0, 0x0, 0xd7340530, 0xce6805c0, 0xce680598, 0x80453f0), at
0xef602a7b
  [29] 0xef602d81(0xce680598, 0x0, 0xce6805f8, 0xd7340530, 0xceb37a88, 0x0), at
0xef602d81
  [30] 0xef602a7b(0xceb37a88, 0x0, 0xd7340530, 0xce6805e0, 0x8045468,
0xd6677951), at 0xef602a7b
  [31] 0xef602a7b(0xce6805e0, 0xceb37a88, 0x0, 0xd7340530, 0xceb37900,
0x80454a0), at 0xef602a7b
  [32] 0xef602a7b(0x0, 0xceb37a88, 0xceb37900, 0x80454d0, 0xd68890d1,
0x80454f8), at 0xef602a7b
  [33] 0xef602a7b(0xceb37a88, 0xceb37900, 0x80454fc, 0xd6888eb4, 0x8045520,
0xd7208060), at 0xef602a7b
  [34] 0xef602a7b(0xceb37900, 0xceb37900, 0x8045528, 0xd263d2f4, 0x8045550,
0xd263d948), at 0xef602a7b
  [35] 0xef602a7b(0xceb37aa0, 0xceb376e0, 0x8045570, 0xf4db8000, 0x8dc2518,
0x2), at 0xef602a7b
  [36] 0xef600169(0x80455b0, 0x8045760, 0xa, 0xd263d310, 0xef608490, 0x8045684,
0x2, 0x8dc2518), at 0xef600169
  [37] JavaCalls::call_helper(0x804575c, 0x8045648, 0x8045680, 0x8dc2518,
0x804563c, 0xf4aa8888), at 0xf4aa8a37
  [38] os::os_exception_wrapper(0xf4aa88b0, 0x804575c, 0x8045648, 0x8045680,
0x8dc2518), at 0xf4aa88a4
  [39] JavaCalls::call(0x804575c, 0x87b7718, 0x8045680, 0x8dc2518), at 0xf4aa8888
  [40] jni_invoke_nonstatic(0x8dc25d8, 0x804575c, 0x8db5158, 0x1, 0x8db9b69,
0x8045768, 0x8dc2518), at 0xf4ab8883
  [41] jni_CallIntMethodA(0x8dc25d8, 0x8db5158, 0x8db9b69, 0x80457a0), at 0xf4bed883
  [42] 0xef054e5d(0x81ee700, 0x8db5158, 0x8dbe878, 0x0, 0x0, 0x80eb9f8,
0x84c94b0, 0x1, 0x8045950, 0x8045948, 0x8045bc8), at 0xef054e5d
  [43] 0xef0558d2(0x8dc2718, 0x8dc1d80, 0x8045950, 0x8045948, 0x8045bc8), at
0xef0558d2
  [44] 0xee665db4(0x8045d1c, 0xee6ed160, 0x8045d28, 0x8045db8), at 0xee665db4
  [45] SbUnoObject::Notify(0x8db0f90, 0x8443b28, 0x8045e48), at 0xf82984d4
  [46] SfxBroadcaster::Broadcast(0x8443b28, 0x8045e48), at 0xfd7b00c9
  [47] SbxVariable::Broadcast(0x8dc1a08, 0x10000), at 0xf830ca87
  [48] SbxValue::SbxValue(0x8dc1a70, 0xf8383d70, 0x8dc1a08), at 0xf8308487
  [49] SbxVariable::SbxVariable(0x8dc1a70, 0xf8383d78, 0x8dc1a08), at 0xf830c595
  [50] SbiRuntime::FindElement(0x87b08e0, 0x8db0f90, 0x8004, 0xc, 0x15612, 0x0),
at 0xf82e960e
  [51] SbiRuntime::StepELEM(0x87b08e0, 0x8004, 0xc), at 0xf82eac33
  [52] SbiRuntime::Step(0x87b08e0), at 0xf82e31d7
  [53] SbModule::Run(0x869e958, 0x87b0160), at 0xf828a906
  [54] SbModule::Notify(0x869e958, 0x8443d98, 0x8046014), at 0xf8289fb5
  [55] SfxBroadcaster::Broadcast(0x8443d98, 0x8046014), at 0xfd7b00c9
  [56] SbMethod::Broadcast(0x869ea98, 0x10000), at 0xf828d2ca
  [57] SbxValue::Get(0x869ea98, 0x8046078, 0x0, 0x17, 0x18, 0x8046270), at
0xf8308bc0
  [58] 0xf651ded8(0x869ea98), at 0xf651ded8
  [59] 0xf65079a9(0x8210ba0), at 0xf65079a9
  [60] 0xf6507a68(0x8210ba0), at 0xf6507a68
  [61] 0xf650a3f8(0x8210ba0, 0x847a188), at 0xf650a3f8
  [62] 0xf6505795(0x86b5988, 0x847a188), at 0xf6505795
  [63] 0xf64fc0a8(0x86b5988, 0x847a188), at 0xf64fc0a8
  [64] 0xf801a915(0x84928f0, 0x86b5988, 0xf65c49cc, 0x847a188, 0x1), at 0xf801a915
  [65] 0xf801d2fb(0x84928f0, 0x847a188), at 0xf801d2fb
  [66] 0xf801d19c(0x84928f0, 0x847a188), at 0xf801d19c
  [67] 0xf8047385(0x8471a30, 0x847a188), at 0xf8047385
  [68] 0xf804734c(0x8471a30, 0x847a188), at 0xf804734c
  [69] 0xfe45d7ed(0x87afcd8), at 0xfe45d7ed
  [70] 0xfe45dd57(0x81b70f0, 0x81cbf20, 0x16, 0x87afcd8), at 0xfe45dd57
  [71] SalDisplay::DispatchInternalEvent(0x80e8420, 0x80e7f50, 0x0, 0xfcd518dc,
0x80c2794, 0x1), at 0xfb685828
  [72] 0xfcd1434e(0x80c6538), at 0xfcd1434e
  [73] 0xfcd1427f(0x80c6538, 0xfefb2000, 0x87af600), at 0xfcd1427f
  [74] g_idle_dispatch(0xfcbcf5b0, 0x2, 0x80e7f50, 0xffffff9c, 0x23, 0x1c5), at
0xfcb74b4d
(dbx) regs
current thread: t@1
current frame:  [1]
gs       0x000001c3 0x00000000
fs       0x00000000 0x00000000
es       0x00000043 0x00000000
ds       0x00000043 0x00000000
ss       0x00000043 0x00000000
cs       0x0000003b 0x00000000
edi      0x08044e50
esi      0xd67a6e6c
ebp      0x08044e40
esp      0x08044e1c
ebx      0x08044e24
edx      0x08044e1c
ecx      0x00000000
eax      0x464c457f
eip      0xef60fc59:0xef60fc59  lock cmpxchgl  %edx,(%ecx)
trapno   0x0000000e 0x00000000
err      0x00000007 0x00000000
eflags   0x00010202 0x00000000
(dbx)