Just wanted to let people know that I have now confirmed that PainlessSVN works in the following versions of Windows Servers:

• Windows 2003 Server 32-bit
• Windows 2003 Server SP1 32-bit
• Windows 2003 R2 32-bit
• Windows 2003 R2 SP1 32-bit
• Windows 2008 Server 32-bit

I haven't been able to get it to work on the 64-bit versions yet.