usb key problem

[PJ]

I am running 7.2 but cannot properly attach/detach cruze 8gb and 4gb USB
keys.
When inserted, generate errors:
da0 seems to be read correctly
but then comes arow of
(probe0:umass-sim0:0:0:1): snip CAM Status: SCSI Status Error
snip NOT READY asc:3a,0
Medium not present
Unretryable error
then
cd0 at umass-sim0 dada,dada,dada
attempt to query device size failed; UNIT ATTENTION, Not ready to ready
change, medium may have changed

# camcontrol devlist
<SanDisk U3 Cruzer Micro 4.04> at scbus1 target 0 lun 0 (da0,pass0)
same as above ----- ---------------------------   lun 1 (pass1,cd0)

Something is not functioning & I don't understand. It did function a
while (some weeks) ago but now, no go...
I did look on the web, but...
????