I sympathize. I too lost several big downloads that cost hours. When they weren't in the LimeWire folder I searched with Sherlock. They weren't anywhere on my computer. Thinking the names might have been changed, I searched for all files changed today. They weren't there either. They evaporated, but somehow LimeWire was satisfied that they were safely saved somewhere.

I would remove and reinstall the software, set the preferences, then test that it is working with some small files before attempting major downloads again. Watch out for the kernel panics I reported elsewhere- best not to have any important files open while LimeWire is on.

tom