Yea, it is a general MSN error, just a coincidence that you had been getting it every time you tried to paste a URL. Sadly, this appears to be an issue with MSN, and I dont know whether we will be able to do anything about it.
well, it depends on the URL -- a url could trigger that. the MSN server blocks urls that look like they might go to executables, because that's apparently the best way MS could come up with to keep Windows users from accepting virus links.