Well I have my incomplete files set to close to a thousand. It's better to be on the safe side. lol
Keep in mind that when you close LW, you must wait for LW to totally close down (which might take a min or 2) before shutting down your computer. Otherwise this might result in corrupt downld preferences.
If you have problems with a computer that crashes consistently (which will also potentially corrup the LW downld prefs), then back up your downld preferences files. These files are called 'download.dat' & '...bak' & are located in your incomplete folder. Make a copy of them & store them else where or off your computer. Then reload them next time before you open LW.