I'll give you my own recent gem which is apparently well known... (and unrelated I think to McGrath's problems)

I wanted to get a hard disk I'd set up for Linux back to Windows 98 (FAT 32). The trusty FDISk Gives you this scenario:

"Cannot delete Extended DOS Partition while logical drives exist"

Try to delete the logical drives you get "No logical drives defined", etc, view - "no logical drives to view"...

I found the 3rd party command line tool aefdisk very helpful.