Reread what I said about the red files carefully. You should not share them as normal files in your download folder or other shared folders. Simply share them as partial downloads only.
Red incomplete files means for some reason LW has stopped functioning with them.

For quitting LW, I recommend in your system tray option to have it set to shutdown immediately, not set to shutdown after transfers. Also LW can take considerable time to close sometimes so give it 5 mins if needed.

Not sure why you'd find a downloads.dat file in the preferences folder, unless LW has changed the location for it in the newest version. I am still using LW 4.16 at present.

BTW if this is happening often, then get this utility: http://www.gnutellaforums.com/genera...os-x-here.html which does same thing, backing up the LW download prefs, so this one should work properly. It did for me on my old computer. (Oh .. not sure if it is compatible with new intel computers though, but worth checking.)