SD Card Will Only Mount Once Per Boot

[Michael Satterwhite]

After Boot, I insert an SD Card into the reader. Shortly afterward, I 
see it mounted as a 1 GB Filesystem on my desktop. It is completely 
usable at that time.

I right click it and select Safely Remove. I then remove the card from 
the reader.

A bit later, I reinsert the card (or another one). Nothing happens, the 
card does not get mounted anywhere.

The card will not mount again until I boot the system. There might be 
something else that would restore it, but I have no idea what that would 
be. After I reboot, the above sequence can be repeated ... ONCE. After 
it is removed, it is unusable until the machine is rebooted.

There HAS to be something else that would work. I'd be happy with a 
manual way to mount / unmount it - ANYTHING is better than this. I've 
tried googling for these symptoms without help.

Can anyone help?
---Michael