Hardy Heron here. I've just bought this on thinkgeek and I was trying to make a flash drive persistent Ubuntu, following this tutorial.
As stated by neverard, I get the same behavior after saving the partitions with the 'w' option:
I receive the message "WARNING: Re-reading the partition table failed with error22: Invalid argument. The kernel still uses old table. The new table will be available at the next reboot.". And I can't see the partitions afterwards.
Thing is I've tried formatting it in a windows environment, specifying FAT32 as neverard says, but the problem remains.
I was wondering if anyone been through this and could shed some light on my newbieness...