So you tried deleting the LW preferences folder (see fixes for LW)??

If you are sharing a lot of files (over 500), & these are in multiple folders, then move some files out of these folders if possible.

Go to LW's incomplete folder & list it by size. Delete all those at 0 KB (later after opening LW you should click on top of Progress column to list all files by % & then delete those at 0%.

Your problem has got me stumped. I'm tending to think it's a Java issue. Do you have a Registry Cleaner b/c your system might need it. Also make sure the HDD's not fragmented.