Ooh, if that's the case, the only firmware I'd risk installing is one directly from Acer for that particular Acer part number.I'm not sure what to suggest, I havn't had any real trouble with a unit similar to the trouble you describe, or the few times I've had some trouble, a full system restart (full power down) would solve the problem.
The only other thing that I can think of that might be similar is I've got one CD-RW drive where the "burn free" option doesn't turn on properly the first time I try to burn a CD, but the second time it does. Not that it matters much - I've never had it produce a coaster in the years I've had it. But the work around that I found (using audio-cd-creater-cdrecord/2) is I've got a small (10 MB or so) ISO file which I'll first run / burn in the "test" mode, where it does not write anything to the CD. It leaves the CD blank, but it does change whatever software switch is in the drive to turn on the burn-free option. Once that completes, I'll then do the actual burn of whatever it is I want to burn and the burn-free option will be properly turned on for that (and any subsequent) burns. I've always assumed this glitch was just something to do with CDRecord/2 not turning on the burn-free option properly the first time around, but who knows...