Also on this topic - because I had the same problem, and the above solution was not enough - here is another thing to do with Limewire to complete this process.

This may be because of later versions of Limewire that this is now necessary...

Go to Tools ---> Options--->Advanced---->File Associations. Once there, uncheck "Use Limewire for: .torrent files"

Putting together both the above suggestion, and this one were successful for me. Hope this helps anyone out there.