USB hub/mem card reader freezes XP start and not recognised?! Mad - please help

Right - I've got:

ASUS P4S800
XP SP2

When I plug in my digital camera, usb hub (powered - as part of my Dell 20001FP), or card reader, there's a huge delay, before the usb sound "bing bong". Then XP may state what I have plugged in after a further delay, however, it usually just ignores it. and I get nothing from it. It means none of the above devices work.

BUT if I have them pluged in on start up; XP wont start - it just pauses forever at the black screen before "welcome", until I remove the device, and it continues as normal. (?!)

THIS IS ODD - if I start in safe mode - they all work.

Please help, as I don't want to reinstall XP.
TIA
MB