If you revert to an earlier version then your download prefs will become corrupted. Options: try to reduce memory taking issues; eg: Tip: Purge the Downloads Queue! (click on link)
Others:
Go to LW's prefs>Speed & tick disable Ultrapeer Cap. & press apply button.
Set both uplds & downlds to autoclear.
Close all LW windows you don't need open at that time.
If you're not in front of your comp, then hide LW in the dock.
Reduce uplds to about 70-80% or more. Reduce downlds to 80 or 90%.
Also don't use the Resume button on all incomplete files. This can have side-fx such as affect LW's connection quality. May queue your files for much much longer. This will also stress LW & your comp. If you use Resume/Find sources then just apply it to a couple or so at one time.