Terminal Service 2008 amd Crystal Report (registry trouble ?)

Hi everyone,

I develop an account software that use Crystal Report to obtain reporting
capabilities. My software supports three runtimes of Crystal Reports:
release 8, release 9 and release XI. The user can configure the application
and choose which to use.

Some installations (of our customers) use Terminal Server features: the
application is installed on the host pc (usually Windows Server 2003), and
the clients (running XP) connect to the host and use the software via
Terminal Service, and all works fine.

Recently one customer of ours has set up a Windows Server 2008, and troubles
began ! ... the Crystal Reports runtime failed to function. Let me try to
explain the scenarioes:

- Host PC with Terminal Service 2008
- User A on a PC with Windows XP
- User B on a PC with Windows XP

scenario 1, my application uses Cristal Report Runtimes XI

User A and B can correctly install the runtimes.
Both of the user cannot print reports due to a failure instantiatìing the
COM components of Crystal Report.

*****
scenario 2, my application uses Cristal Report Runtimes 9 ... the most funny

User A connect to the host, install the runtimes and start to use the
application. All works fine.
User B connect to the host, install the runtimes and start to use the
application. User B can use the application (and print reports) but suddenly
the User A failed to print (failure instantiatìing the COM components of
Crystal Report).
Well ... User A reinstall Crystal Reports library and newly register COM
components, and the application newly works fine (and print reports
correctly) ... but User B suddenly stop printing reports (the same error).
User B reinstall Crystal Reports library and newly register COM components,
and the application newly works fine (and print reports correctly) ... but
User A suddenly stop printing reports (the same error) ... and so on.

*****
scenario 3, my application uses Cristal Report Runtimes 8

User A and User B can correctly install the runtimes and the software works
fine !

*****

Very funny beacuse ver. 8 of Crystal Reports Runtime are quite old, but they
works properly instead of rel. XI (more recent) that doesn't work at all !
Crystal Report runtimes use heavily Windows Registry, and setting up those
runtimes require a lot of registry update (due to COM interfaces); maybe
there is some registry issue/trouble that scramble Crystal Report runtimes
configuration ... the scenario 2 is quite bizarre and counfuse me !

Shall I need to configure some setting on Terminal Service 2008 ?
any idea ? thank you very much.
Paolo