Processor: 1.93Ghz Intel Core 2 Duo
Memory: 1GB 667Mhz DDR2 SDRAM
Graphics: SIS something or rather (I know its not supported)
Wifi: Ralink Technology RT2501USB (pnp ID 2573)
Using kernel extension "Ralink RT2500 RT73USB"
(I had to delete the "Replug" extension as it caused panic on boot)

Wired: Realtek RTL8139


Actually... after thinking about this and going through the list, along with wat you said about network drivers, I have a feeling it may be the wired ethernet driver, as after I rebuilt, I also included the RTL8139 driver, I should have thought of this before.

When the trouble started, I got rid of the wifi extensions, but not the wired, so I'll give that a go now, and report back.