Wow, Microsoft patch team has been busy with the fixes and patches for SQL lately.  The whole SP2 and subsequent fixes/patches/refreshes has caused quite a bit of confusion.  Not knowing what the latest version is really makes it difficult for a DBA to keep on top of the server. 

Fortunately, Steve Jones of http://www.sqlservercentral.com has compiled a list of fixes and versions to help us out.  To determine your version just connect to that server and then is a query windows type

          Select @@version

The result will be a string with your SQL instances' version that looks something like

          Microsoft SQL Server 2005 - 9.00.3050.00 (Intel X86)
          Mar 2 2007 20:01:28
          Copyright (c) 1988-2005 Microsoft Corporation
          Developer Edition on Windows NT 5.2 (Build 3790: Service Pack 1)

Then match that with what Steve has compiled at http://www.sqlservercentral.com/columnists/sjones/2960.asp and you can find out where you stand.