Hallo,
dies schon mal am CRM Server ausprobiert?
There is a problem with one of the hotfixes. Here is how to fix it.
The issue was related to Hot Fix KB 912061
Steps to resolve the issue
1. On the Microsoft CRM server, click Start, point to All Programs,
point to Administrative Tools, and then click Microsoft .NET Framework 1.1
Configuration.
2. In the navigation pane, click Assembly Cache.
3. Click View List of Assemblies in the Assembly Cache.
4. Right-click the Microsoft.crm.MetadataService assembly, and then
click Delete.
5. Reboot the server if necessary
# in einer anderen Installation soll dies geholfen haben