One of our techs had a Exchange 2003 SP2 server that the OWA quit working and I suggested that he do a Exchange 2003 reinstall. That usually clears up any of these quirky Exchange 2003 problems if you can’t get it correct and of course when he went to install SP2 got the “there is an earlier version of the exchange intelligent message filter installed” So I had this fix for a SBS 2003 Server which it is still Exchange 2003 and this allowed him to get SP 2 installed. http://support.microsoft.com/kb/935916
He got this all done and the OWA would come up but with a 500 error inside and from the outside I would get a “The requested resource is in use.” Error so I did a quick search and found this and this corrected the problem for him regsvr32 %windir%/system32/vbscript.dll life was good and now he has his weekend back.
Til Later just Roger