[X4U] Can't erase SanDisk

[Crandon David]

I have a friend who just purchased a 1gig SanDisk Cruzer micro USB  
flash drive. He's trying to get rid of all the software that SanDisk  
puts on it.

He's reformatted it, but there still remains a 28Mb or so "disk  
volume" (it appears as a seperate volume on the desktop from the  
usual SanDisk volume) that contains some PC files/programs.

We can't figure out a way using Disk Utility to erase that volume.  
Doing a Get Info on it indicates it is locked (as is the SanDisk icon  
as well). All the Disk Utility options are greyed out.

Can anyone help?

Thanks,

David