I've had problems with pro and couldn't get lm to help. I downloaded WinMX and it works great. On a side note, I figured out my own problem and fixed it myself (port assignments). I switch back and forth between lw and MX because they both have their slow times and when it gets slow on one, I switch to the other.
I too have a massive music collection. Only about 1/10 is on my HD because of space constraints. I guess I have somewhere around 2000 cds.
Anyway, check out WinMX. It's a winner!