Thanks for the uninstall tips. I'll keep your suggestions should I ever need to uninstall Limewire.

I've already taken the 'pain-and-suffering' trouble-shooting approach, by erasing the hard drive (having a bootable duplicate of course), reinstalling the system software, and then reinstalling all of my third party applications one-by-one to find the offender, omitting Limewire installation during this process, which unfortunately I performed alphabetically. As it turns out Virus Barrier, version 5, is to blame, and Time Machine functionality returns as soon as Virus Barrier is uninstalled. Time Machine works fine with Version 4 of Virus Barrier.