USB Mass Storage Device won't Eject/Unmount

My brother bought a Sanyo ICR-B180NX digital voice recorder last year to use with his iBook. It was working very well up until about August of 2005. At that point, the recorder would mount on the desktop, and he could get all the files off (it records direct to MP3 format rather than WMV, so he can edit his files very easily), but when it came time to eject it, the device icon would disappear and then immediately re-appear on the desktop. The display on the voice recorder remained static at the "Connect" screen.

I believe this happened in conjunction with some sort of OS update, as it was a "sudden" thing. We can't quite recall what happened between the times it worked and the time it stopped working.

I have tried the device on a PC, and it works the way it should, so I don't believe there's anything wrong with it.

Now, I know the system requirements on the website say that you must have Windows, but a statement from a support company (we returned it to the place where we got it, and they sent it out for repairs, and it came back with a letter) states that the device does act as a generic Mass Storage device, and thus may work with most systems.

All my other USB storage devices (ie. SanDisk 12-in-1 card reader, SanDisk Cruzer Titanium 2GB, iPod Photo), and FireWire devices (ie. WiebeTech TrayDock Extreme) work fine and unmount fine.

Does anyone know of any changes to the way Mass Storage devices are ejected in the current iteration of the OS? I haven't had a chance to test the device under an older OS, but will soon.

Alternately, if anyone has any suggestions regarding replacements (not really looking forward to that, given this recorder cost almost $300CAD), let me know. We need a device that can plug in via USB and transfer files to his iBook which he can edit together (he's a newspaper reporter in training, and needs to edit the interviews to take out such things like dead air, etc).

Thanks!
Mike Ma.