[captain_obvious]Did you try cleaning the drive's lens?[/captain_obvious]

Seems more likely than a firmware bug.
Wrt firmware reflash/upgrade - if the drive's manufacturer lists nothing, Fujitsu lists nothing, and searching for
any firmware version for your drive returns nothing, you're left with asking someone else with the same drive to read the firmware for you (good luck with that). It's been a while since I've
tried flashing optical drive's firmware. Back then I tried mtkflash and xsf which worked in real DOS only. There also seems to be a utility called
flasher apparently more modern and working under WIndows.
A quick search reveals quite a few topics on problems with this drive, so if this is all too much hassle and it's under warranty, have it replaced and be done with it.