I treid power-off power-on (reboot) and no help. Best I get is the external SD card, nothing internal. Only get internal if/when pull the SD card and battery, return battery and plug into a particular USB port! Using Motorola cord that came with Bionic - things were not even this good with other cables.
Asked Motorola about it. They sent me to a page where it says to ONLY use the cord that comes with the phone. They go on to say that if the procedure doesn't work, do a factory reset! I would rather pull the SD card and read it directly every time than do a factory reset (it takes so many hours to get settings right).
Here is the Motorola page (and I think its aimed at 2.2, not 2.3):
ANDROID 2.2 - Can't Connect to PC
I think there are some 2.3 pages about this issue.
We gotta keep asking Moto to fix this.