LimewirePro is SLOW

Hi, im sorry if i put this question in the wrong side of the forum and if i did please guide me in the right direction lol. well for my question now...I have Limewire Pro Beta 4.13.4... well when ever i try to download big files it starts at 50-80 KB/s but maybe 15-20 minutes later its going at 1 KB/s and sometimes it just completely stops and it wont download. Is there a reason why its doing this? Is there a way i can fix it? Any answers would be greatly appreciated