in case you refer to that Microtec card reader mentioned in the topic's title:
Kodak used these drives in 'picture stations' in local shops to make prints from customers' flash cards. When they stopped using SCSI, tons of these drives appeared very cheap on eBay and such. They look identical to the regular unit, but are software locked as read-only.
Such a (formerly Kodak) drive must be flashed with a write-enabled firmware.
Otherwise it won't mount because the desktop file can't be written.
The firmware should still be downloadable. Iirc I have the PC version somewhere.