problem using bearshare with vista

i just bought a new dell and it came with vista on it, i still have my old dell which has xp on it. i am using bearshare 5.0.0 which has been the best for me on xp. however i when i transfered the program to my vista os, and start downloading, it takes longer. my internet connection i understand is faily slow due to the fact i am in Iraq. however when i download from bearshare on my xp os it takes about 10 hrs to download a 350mb file, when i try with vista it takes 5 to 6 days. they both are on the same network connection with wireless. how is this possible? please help. Thanks.
p.s. it does the same thing with limewire and ares.

Your best option right now is to change the new computer to XP.

I'm using the 6.1 version on a Vista home edition without any problems....

The 6.1 version is a counterfeit. Try the original and you'll see it is on a totally higher level of
performance, not to mention it is free of ways to loot your credit card.