Hi Hermanni,
Yes I did compare User Agent and XML Manager also.
And the problem is solved!
I localized the error to a specific transformation, I did copy the content of the XSLT-file from a working domain to the one that failed, and viola! it worked like a charm. The file has not changed since I exported the service from a working domain to the one that failed. I can't understand why it suddenly works now.
/Jocke D