Flash Drives Failing since installing Mountain Lion

[TheChisholm]

I have four 2GB flash drives that have failed since I installed Mountain Lion, and all fail with the same problem. When I plug in, I get the message:

Mac OS X can’t repair the disk “Untitled.”
You can still open or copy files on the disk, but you can’t save changes to files on the disk. Back up the disk and reformat it as soon as you can.​

I have tried to delete everything from the drive, but it is now showing up grayed as if it is read-only. I have attempted several things in Disk Utilities, including First Aid/Verify Disk/Repair Disk. The message says "Volume Repair Complete", but it still will not let me read/write/delete.

If I try to erase the drive (set to MS-DOS FAT), I get this message:

Volume Erase failed
Volume Erase failed with the error:
Couldn’t modify partition map.​

I have also attempted to reformat on a PC, but the error message there is that the drive is locked. On the Mac, I have gone through sharing, users, and Get Info, and it does appear to be in a read-only setting, but I can't find how to remove it.

If anyone else has had these problems, but more importantly, have found a solution, please let me know.

Thanks!

 

[justperry]

Make a screenshot of the Get info panel on one of the Flash drives and post here.

There should be a padlock to unlock to change Permissions, also a checkbox to ignore ownership.
Normally I drive should not be locked, a folder and file are easy to lock in the Get Info window, a Disk not so much.

Edit: Screenshot of window, Command-Shift-4 then hit spacebar and click on info window.

 

[TheChisholm]

Screen Shot of Info

This is what I see.

Under Sharing and Permissions, I get "You can only read", but I see no way to change that.