Not exactly a Buffalo drive, but my problem seems very similar, and I'm convinced it occurred after a recent operating system update.
I have a Tascam DP-01FX that I use infrequently and that functions perfectly. I have used the USB connection to transfer files back and forth to three computers; and old G4 Mac (now out of commission), a new iMac (running OS 10.5.8, and an old Dell Inspiron 5000 (running Windows XP). The last time I tried to connect it to the iMac, the System profiler indicated it was connected, but it never mounted on the desktop, and it could not be made to appear in Disk Utility. I tried all varieties of connection; through a high speed hub, directly to the computer (with ALL other USB devices disconnected including the keyboard), etc. I zapped the computer's PRAM, verified and repaired permissions on the system drive. I even unplugged the computer and everything connected to it for half an hour, then reconnected and zapped the PRAM again. Nothing I've done will make the Tascam device mount on the desktop. However, it mounted with no problems on the old Dell Inspiron 5000. The kicker is that I've successfully and easily used the DP-01FX on the iMac on a previous occasion. All this leads me to believe there is something in an Apple software update that is causing this problem. All other USB devices work flawlessly, including an external hard drive that I only use for special projects about once a week. It mounts and un-mounts without any problems. This has got to be an Apple "oops."
