OOo 2.0 introduces Private (and Public) keywords in a Sub (or Function) definition. 
This is described nowhere but some programmers begin to use it.
This bug occurs during macro development and can be very disturbing. Steps to 
reproduce:
The following macros are defined in Standard library of a Writer document.

- in Module 1 create this:
Option Explicit

Private Sub Main1
  MsgBox("macro Main1")
End Sub

- in Module 2 create this:
Option Explicit

Sub Main2
  CompatibilityMode(True)
  Main1
End Sub

- run macro Main2. Of course there is an error "Variable not defined" because Main1 is 
Private.

- suppress "Private" in the definition of Main1. Run the macro Main2 : still an error 
"Variable not defined". This is incorrect because Main1 is now implicitly Public.

- add "Public" in the definition of Main1. Run the macro Main2 : still an error 
"Variable not defined". This is incorrect because Main1 is explicitly Public.

- save the document now, close it, reopen it. Run the macro Main2 : no error. This is 
correct now!