1. have you got any hardware installed that could be causing a resource conflict - IRQ15, I/O port 170, DMA channel
2. If you go into device manager with a hard disc attached to the secondary ide controller, do you see any indication that Xp has detected a problem?
Otherwise, basic troubleshooting applies - reduce to essential components (motherboard/cpu/ram/video card) try your current boot disc only, first on the primary channel - then swap it onto the secondary channel using the same cable and see if anything changes. If it does, then it would indicate a hardware fault but I'd be suprised if this was the case.
Otherwise, you keep making small changes back to your original config, one step at a time until the problem reoccurs.
Let us know how you get on
hth