I too have had this problem since upgrading to 4.12.3 which I only did on advice from here. I have followed all the advice i.e clearing incomplete, deleting prefs etc etc. and I posted a thread about it. today downloaded one file started another and booff gone.

getting to the stage where I might bin it altogether, more trouble than it's worth. glad I didn't get pro now

here is the orignal thread
http://www.gnutellaforums.com/showth...8&goto=newpost

last entry says 4.12.4 is available