Can someone please help?!?!

New to limewire after being recommended by a friend. Every time i search for anything i get loads of results however when i try download, it comes up 'not enough sources' every time. Yet when i disable my firewall / antivirus protect they download fine, and carry on downloading once i re-anable my firewall/internet security. i've read the other threads and can't see anything specific to this. would be very gratefull for any help, been playing about all day now Thanks!!!!!

OS - Windows XP Pro
Notron Internet security / firewall
Latest version of limewire
ISP - NTL Bband. (internet explorer) think thats all?