Problem with SanDisk Cruzer 64 GB - Write protect Error

Plugged a Brand New Disc Cruzer 64GB Flash drive into my PC and start to copy 20GB of small file accross after about 200MB it failed with a write protect error.  When I plug it back into my PC it doesn’t reconise it and when I plug it into my MAC it is only read only.

All over flash drives work in my PC (HP , Lexar, and a couple of unbranded ones) with no problem.  We have bought a batch of these at work, think I had better suggest sending them back as it is now un-usable after copying 500MB of data across!!

Or Is they anything I can do to fix it ??

Cheers

Payneardo

PS My other flash drives are working fine !!