Hey,
I'm running a Dell Mini 9 with a moderately nLite'd version of Windows XP Pro SP3 (with all latest updates). I keep getting intermittent hard locks when an SD card is present in the JMicron JMB38X card reader (verified by running the PC for 24 hours with no card, and 12 hours Memtest86+ to exclude faulty RAM).
Looking through the Event Viewer, I see lots of these errors like the one below - full pics of the errors are here: 1, 2, 3
EDIT - apparently this is "normal" power-saving behaviour according to JMicron support. When these errors occur the entries for the card reader in Device manager disappear (when there is no card present).
HOWEVER, the hard locks are definitely related to the presence of my SD card in the reader... will need to experiment with different cards to work out which of the two is the problem I guess!
Cheers,
Suman