Mitsubishi MF355F on IIgs - problems

[vector <abuse@aol.com>]

I've bought a couple Mitsubishi 3.5" manual-inject floppy drives, model 
MF355F-3520MA, the kind used in Starmax computers and some new Macs, to 
experiment with my IIgs.  I opened an external 800K Apple 3.5" drive and 
swapped out the drives.  My results were disappointing.  

If I insert an 800K ProDOS-formatted floppy, GS/OS will recognize that a 
disk was inserted and allow me to browse it and read files from it.  Under 
no circumstance, however, can I get the disk to eject properly.  It wasn't 
too surprising to find out that the eject button didn't work, but the 
Finder menu option "Eject" didn't work either.  In both cases, the result 
is an endless cycle where the drive activity light burns solid red for a 
long time, then blinks off - repeat loop.  This doesn't actually LOCK the 
computer, but the mouse is VERY slow to respond.  The only fix is to cycle 
the computer's power off and on.

What could be going wrong here?  I thought these drives were supposed to 
offer better compatibility than this.