Problems with referenced assemblies in Workflows

When registering plug-ins, CRM doesn't always look for referenced assemblies where you think it would. It can look for "some" dll's in CRMWeb\bin folder (but not all references for some reason) as Gustaf explained in his blog.

But there is one more deviation, and that is when registering Workflow plugins, CRM looks for referenced dlls in "x:\Program Files\Microsoft Dynamics CRM\Server\bin", and not the "assembly" folder where you put your Plug-in assembly.