Hmmmm.. When I try to use HDToolbox it finds the drive but cannot determine the size of the disk and then when I try to format it never completes the format job and I have to shutdown and restart the machine.. I can't tell if this is a problem with the media or with HDToolbox....
I remember SyQuest cartridges having an absurdly high defect rate - probably 1 in 4 of mine croaked right out of the shrinkwrap. Got any other cartridges to try?