freeze / lock up when plugging in any USB device

[Cooper Strange]

I did a couple more experiments, but plugging in a USB media device 
still locks up the computer. I tried some new things to see what 
would happen.

I tried my USB devices in Knoppix to make sure there was nothing wrong 
with the hardware either in the computer or my USB devices. Knoppix 
for some reason did not recognize my multi-card reader, which worried 
me at first that something might be wrong in the computer's hardware. 
Then, though, all was normal when I booted up Knoppix with an 
external hard drive.

So, I tried more experiments in Fedora 6. To have USB devices mounted 
as the user's, I usually plug them in once logged into the user's 
GUI. That was when I had the problem. So, I tried booting up with 
them already plugged in.

With a multi-card reader plugged in:
Funny enough, once I logged in, there was nothing there. Usually, if 
you boot up with USB media plugged in, it will be mounted, though 
under root, I think. I do not remember. If I booted up with the card 
reader plugged in but no cards in it, no problems, but once in the 
GUI, if I plugged in a card, nothing would happen. If, once I was in 
the GUI, I plugged in the card reader, even without a card in it, 
everything froze up, as before. It did not even need a card in it to 
lock everything up.

With an external hard drive:
Mostly the same as the card reader, but since I knew the device name 
for the external hard drive, I tried a couple different tests. I 
booted up with it plugged in, and then once in the GUI, from the 
terminal, I was able to mount the device manually.

So, I can now get to data on my external hard drives and USB flash 
drives, but unless I knew the device name for all the little ports on 
the multi-card reader, am still at a loss there. I can only plug 
things in, boot up, then manually mount as root. Then, I guess, I 
could use chown to change the owner to the user so the user could use 
all the files and write to them.

So, does anyone know what the bug is here? Why does everything lock up 
if I plug in USB media once in the GUI?