Well, I guess my LimeWire does "scan" al those files however a lot faster.

On the other hand if you're limewire is recalculating the checksums everytime it's doing that a lot faster than mine does. If i add a few files I can actually see it happen file by file and for 500+ files(depending on file size off course) that would probably take over an hour.

So I guess I can't help you. sorry.