[eluser]tedroche[/eluser]
Yes, if it's possible for you to specify the versions of software on the server, you can stick with the older versions, although there are reasons why newer versions have come out; bug fixes and security fixes will be missing from the older versions.
But if you're stuck with the newer versions of PHP on Windows with MS SQL Server, you'll need to look at the new "Microsoft Drivers for PHP for SQL Server" and that's what I'd like to see pushed into the CodeIgniter framework, so we all have it as an option.
As for SQL Server versions, Aken, yes, it's hard to keep up with Microsoft and their versions, but for support and security fixes, it's pretty important to keep up with the current version or the previous one. In calendar year 2011, we shouldn't be running SQL Server 2000 or 2003. Easy to say, not always easy for the customer to implement.
