You can try removing them, but I'd be really surprised if it still works the next time you connect. You can remove it from HKEY_CLASSES_ROOT\CLSID\{0b91a74b-ad7c-4a9d-b563-29eef9167172} since the one at CLSID should cover that one also.
However, I wouldn't be anywhere near as concerned about having Users in the CLSID permissions as adding LOCAL SERVICE to the Administrators group.
We'll continue to try to find the root problem, so check back for more info.
Zune Product Team
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