Well I don't know if this is of any help,
I had no problems running 1.5 in winME, maybe becouse I keep my system clean with adaware, and i am a Phex fan, so I had a java runtime enviroment installed. ( ? )
But I recently installed win2K as a 2nd os and I decided to install limewire1.6 in it but it appears to be more buggy than 1.5 .
The screen is flickering when a search is performed and the programme seems to respond more slow when it runs for over 1hr.