Honestly,I have no exposure to CR 9.0 version and,neither can I try experimenting on it as I do not have it with me.But,I do realise that CR9.0 ;though considered to be more powerful than ever before, is causing problems for users during installation.I have already received a couple of similar queries related to this.
I would suggest that you try re-installing Crystal Enterprise 9 on the Server machine.If one installs the CR (in Version CR 8.0 and older) & CE(in Version CR8.5 and newer) ,after installing IIS ; the DLL's should get automatically added to the Web Server.
I would also suggest that you should go through the Hot Fixes available for the latest versions and apply them to your work environment.You can achieve this by going to Crystal Decisions and, Select Crystal Reports (Version 9) from the list.
Pooja M.,
http://home.attbi.com/~pooja.mohan