Assuming the disk is not 1.38MB of bad sectors, after inserting the disk, don't mount it but instead check dmesg to see which device it's being attached to. Then run ls -l on that device. For example if it's /dev/fd0 (which it likely is) you would type
Look for the first letter to the left of the permissions. It should be a b to indicate a block device. I've had some issues in the past when my floppy disk or flash disk would be detected as character (c) instead of block (b) and would cause a hang when trying to mount it.
In a distro that used udev it's not too difficult to write a custom rule to force a device to use the block subsystem.