SD card not seen by system after unmounting

Sun Mar 6 18:49:20 UTC 2011

This is wierd. I've got a multicard reader installed on my Fedora 14 
system. If I insert an SD card, it gets recognized and mounted right 
away. If I unmount the card, remove it, and reinsert it, the system does 
nothing. No entries in the messages file about the device or anything. 
If I want to use the SD card again, I have to reboot.

Has anyone seen something like this before? Ideas on how to debug the 
problem?