Thanks for the detailed information. It'll definitely help with trying to figure out what's causing this error.

Just to be clear, you're saying that in the download area (the place underneath the search results that lists the files you're currently downloading), the filename of the download is listed as "T-#-#-name"? And, when you try to delete the file from the incomplete folder (or more precisely, rename it and then delete it), it reappears the next time you start LimeWire?

Off the top of my head, I'd say to make sure LimeWire is closed, then delete the incomplete folder entirely. The next time LimeWire starts up it will recreate the folder. This will force LimeWire to forget any information about what it was downloading. To be extra careful, search your disk for a file named "downloads.dat" and "downloads.bak" and delete any files that you find and are in a folder called "Incomplete".