I don't think it's wise having more than one version of LW on the one computer. Unless perhaps they're under different user accounts, but still... It means that you could have 2 events of LW running or attempting to open simultaneously & are clashing with each other.

Also, jumping back to LW 4.0.8 from 4.2 or later could corrupt your preferences, particularly your download preferences; download.dat & bak. This happened to me.

May I suggest you get rid of these xtra versions of LW & delete your LW preferences folder; instructions here: Fixes for Limewire & also update your Java to 1.5