Setting special permissions for USB flash device
 

I have a couple of questions, and I have done research on both, but can't quite pull off what I am trying to do.

First off in Suse 9.2 when I unmount my flash drive, I can't remount it on the same USB port unless I reboot my machine. If I plug it into another USB port it mounts again just fine. This is whether I issue a umount /dev/sda1 or not. Any ideas on that? Relatively fresh suse install only a few weeks old.

Next, I am trying to convert to carrying my ssh private key on my flash device. I need to have access to it on Mac OS X (already working), and on trusted Windows machines (already working), however I am having issues with the linux size. I still have it formatted as FAT due to the cross platform nature.

The drive mounts fine, and I have full access, however ssh wants the id_dsa private key to have 600 for its permissions. I have tried some items like creating an fstab entry, however udev seems to be overridding that. I also tried modifying /etc/udev/permissions.d/50-udev.permissions, but that only modified the permissions for /dev/sda*, not for the actual directories on the flash, which still showed as 755.

Any ideas how to do this?

TIA!