I have similar problems. Tried LW basic then Pro and same problem. Back to basic now.

Using win 98se, 1.8gh cpu. LW loads ok and goes for downloads. Very slow about 1 to 3k from up to 5 hosts. Reconnects many times and waiting many times. After LW been running for a while everything slows down. When I try to use my email spamkiller up pops a windows message " Buffer Full' and the program won't work. Get out of the program and try IE6 and I can't get anywhere.

Exit LW and reboot. Everything fine and super fast with my DSL. Run up LW again and the process repeats.

Why is LW causing this buffer full message from windows and killing everything. It only happens when LW is running. I have tried killing all programs but LW and the same thing. I have checked all settings in LW options and all are fine. Something in LW is causing this buffer full which slows all down and eventually kills everything so I must reload. Any one else experienced this problem.