I am comparing the YIELDDISC function for Excel 2000 and Calc in OOo 1.1.0. 
Both the applications run on the Windows 2000 Professional.
 
Let's say:
a) Settlement = 01/01/2001
b) Maturity = 12/31/2003
c) Price = 100
d) Redemption = 300
 
The results in Excel are as follows:
Basis 0: 66.6667%
Basis 1: 66.7276%
Basis 2: 65.8135%
Basis 3: 66.7276%
Basis 4: 66.7285%
 
The results in Calc are as follows:
Basis 0: 22.2679%
Basis 1: 22.2882%
Basis 2: 21.9829%
Basis 3: 22.2882%
Basis 4: 22.2885%

The results in Calc are incorrect.