Help with USB access problem

This may not be the best forum for this since I know the root problem - my
fat fingers - but I got myself into a very strange problem with USB
devices. The system was running OK and VirtualBox sessions can still
access the USB system just fine so the hardware is functional. The problem
is that after some twiddling trying to get the sound system to work better
(11.1, 64 bit on an AMD X2) I wound up sticking my fingers somewhere that
made the system a tad irritable. The problem goes pretty much this way:

Boot up, let the thing settle down then plug in a USB stick. After an
unusually long time and what appears to be 2 distinct access sequences to
the stick, the icon pops up on the desktop. /media has an appropriate
entry made but but I get an error message indicating an access error. If I
chose to remove the device, the safely remove obliges and wipes the icon.
If I then re-insert the device, I get the same slow song and dance but now
the /media folder contains a second mount - the first one was never erased
upon removal. There are also two .hal files (.hal-mtab~
and .hal-mtab-lock) which would seem to indicate that the problem is in the
hal sub-system.

How do I go about a. figuring out what the problem is and b. how do I go
about fixing my screwup? I know just about enough to be dangerous here
(obviously) so I’m trying to learn something before exercising the nuclear
option and re-installing <g>.

Will Honea