Here's my PC configuration right now.
IDE0 IBM 14,3GB 7200 rpm UDMA33
LG - CDRW Drive
IDE1 WD 40GB 5400 rpm UDMA66
PC-DVD Creative Dxr3
Last week I bought a new HD (WD 40GB 5400rpm UDMA66).
After installing it everything went fine. A few days later I noticed when I started windows it stopped right after the graphic windows logon (the window after the text mode).
I "reset" worked fine but as the days went by I got many BSODs with "IRQL_LOSS_OR_EQUAL". Since then I tried everything... both hard drives in the same IDE channel, master/slave....
The only solution I found is to disconnect the new hard driive. I ran tests with some disk tools I downloaded from Western Digital's web site and everything is OK.