box slows to a halt... eventually

Phex is my first choice for gnutella access. I've tried 5.3, 6.0, and 6.2, as well as Xolox 1.15, gnucleus, and limewire .... all with the same result. It starts off fine but, after running for 1 to 10 hours the computer grows too sluggish to respond and must be physically turned off (ouch).

The specs: win98se, p3-500, 256ram, cable modem, JRE 1.3, zonealarm set open for client & server.

In each program I've tried reducing the bandwidth as low as 10kB down, 2kB up. I've cut the number of connected nodes as low as a max of 4. I close searches, and have left just 1 file to be downloaded. I allow 1 upload and only share about 12 files. The only odd bit is that the files are large, 100mB+. One program at a time, nothing else running on the box (except zonealarm and norton anti-virus).

Obviously with the same problem occurring across this many programs I have to conclude that it's either me or my box that's fouled up.

Any clues???