I have a 64 MB USB Pen Drive which I was happily using to transfer PowerPoint files from my G4 to Wintel machines running LCD projectors at meetings. Since updating to Mac OS 10.1.4, I've been unable to delete any files on the pen drive from within OS X (the workaround has been to re-boot into OS 9 and re-format it). When I try to trash anything on the pen drive I'm told the file 'can't be deleted'. Under privileges on the get info panel all the read/write options are dimmed, even though I'm logged in as admin (Owner: myname, Group: wheel). I'm sure this is something simple, but it's not obvious to me - why should I be able to re-initialize and/or erase other media attached to the machine but not this 64 MB solid-state hard drive? Using Disk Utility, the drive shows up as locked. The physicial DIP switch on the drive is not locked, and I can erase it in OS 9 or on a Wintel machine.
Running OS X 10.1.4 on two G4s (450 and 733) and a G4 Powerbook 500 - same problem on all machines.