When I try to resume a file from Incomplete file in Library, it says this is not a valid file and it cannot be resumed.....what up? do i just cancel, delete and start over?

Why are you resuming from the library? Normally only do that if your downloads refused to load into the download window. If you have a file that behaves like that, then it may be a PREVIEW file which are stored in the incomplete folder. Else, something about your download.dat prefs became corrupted. So yes, delete. Perhaps start again if you don't already have it.

i was trying to resume an incomplete file from the incomplete file list. when i log on to limewire, some songs need to be resumed so they can complete downloading? so when i click resume, it will say "this is not a valid incomplete file and cannot be resumed" must i always give up what is already downloaded and start again? is there something i can do to head this off or do i just have to delete and start again?
I do appreciate your time and wonderful help.