Licensing problems

[Riggy]

Hi Limewire forum, first post although I have been using limewire for a number of years.
I bought Limewire Pro about 6 months ago.
For the past couple of weeks when I download music then try to play said download, I keep getting "FastMP3player.com" pop-up window which won't let me download unless I concur that I am over 18 and do I agree to recieve mail from them (two tick boxes. Obviously I tick the first box (age) and untick the other already-ticked box and try to play....then a 'Malware' alert from Avast starts screaming at me (Win32-adware-gen) and whatever option I pick, no replay is possible without this damn window appearing every time.
Is anyone else getting this?
Thanks in advance
Riggy.