After installation SP4 people got error messages that IIS was unable to load the ODBC drivers. As far as we know, this will be caused by two ODBC driver files located in the \inetsrv\server directory (names are odbcint.dll and odbccp32.dll). This files are duplicates of the same files residing in \winnt35\system32. Everything works fine as long as these are exact duplicates. However, there were some other ODBC components introduced with SP4 (probably SP3 also) and here the trouble starts. Depending on which version of the drivers will be loaded, everything works (as equal versions of the driver set is in memory) or you get the above mentioned ODBC error (the driver set has different DLL versions in memory that don't cooperate with each other).

The current solution is to delete the two files under \inetsrv\server. Everything works nicely after deletion. HOWEVER, this is not Microsoft's official approach (as far as we know there is no official solution....). There might be a reason for this files to exist under the server directory and as such you might run into some trouble later on. But this might be better than the trouble you are already in...