Hmm. That sounds strange to me. In fact we are planning to move to new version 7.6 to be able to switch between our main setups and setups created within our virtual desktop infrastructure. And we also use desktop authority capability to build custom signatures. We haven't gone any further then that structure listed there in Scriptlogic's knowledge base Q13484 article. We are currently testing it exactly with intention to discover such troubles as you describe and so on, but luckily haven't experienced anything harming our setups. We are building new virtual setup and are interested in such info to prevent ourselves from recovering after upgrade. Probably we have different setup so we haven't experienced troubles on that our test setup. By the way, have you contacted their representatives? What are they talking about that problem you experience? Have you tried to search through the knowledgebase to find out the origin? Don't forget that signature should be assigned after you create the mail profile, so in fact it'll be assigned on the next logon after the creation of profile.