>>A security issue?
>
>Very difficult to say at this point as it could be anything.
>
>>- Did you register the DLL as an admin (if you used regsvr32 in a CMD window, did you run the CMD window as an administrator?)
>
>Yes, on one server I tried it, my account was an administrator. This is the account I used for registration. On the other test we did, the person also had full privileges on the PC.
>
>>- Is the account that generates the error a local admin, or a limited user?
>
>If was not the local admin account. My account however is part of the administrators group. Can it be that I have to switch off and use the local admin account for the registration?

I don't register COM components very often but my understanding is you have to use an account that has local admin privileges. It does not have to be the local admin account as long as the account you have is at least part of the local admin group (if not the domain admin group, if there is a domain).

If the server is 32-bit Server 2003 and you used such an account that should work.

If it's Server 2008 and you're using regsvr32 in a CMD window, you may need to start that CMD window as an admin before running regsvr32.

If it's 64-bit you might have to run regsvr32 from the SysWOW64 folder: http://support.microsoft.com/kb/282747