I have a customer who is in the process of changing their server from Windows 2003 32-bit to Windows 2008 64-bit. Most of the attached PCs are Windows XP 32-bit, with a couple of Windows 7 32-bit. The current server uses FB 1.5 and I see this as an opportunity to switch to one of the version 2 variants. The program that is to be used is written in Delphi 7 using IB objects and, being used in the past exclusively with FB 1.5, does not use any of the new functionality used by version 2. There is also a web program connecting using PHP 5 and using ADOBD and php-interbase.dll.

Can anybody advise me which version I should use (i.e. 2.0, 2.1 or 2.5) and whther I should use teh 32 or 64 bit server version?

Also, are there any problems or pitfalls I should be aware of?