I got burned a second time on cheap USB flash drives, but this time I got a refund! FAST. When my 2 no name 4GB flash drives arrived, it soon become obvious that they wer corrupting files like crazy. A bit of research at www.everythingusb.com taught me a few things: First.. This is a common problem for USB flash drives AND mp4 players. Second: Formatting and FDISKing under windows wont help! The controller chip on the flash drive has been hacked to show a fake capacity. Files that exceed the REAL size just overwrite the earliest files. This is not a production error - this is Fraud! Also.. you wont get the real capacity back unless you can find the production software for the particular controller chip in the Flash drive. And guess what, a fake drive will probably have the wrong s/w bundled with it, to keep you from playing with it. The s/w with mine also installed itself to auto-start on windows start every time, and generally acted nasty.. Guess what my opinion on the bundled software is.. So how do you check your flash drive? If it is one of the no-name cheapies, chances are it will pop open with a little pressure from your fingernails.. Then you can look up the NAND memory chip (the biggest one) on google and divide the capacity by 8. So.. your 8GB nand is a 1GB flash drive, 4GB is 512 etc. Of course you've forced the drive open, the scammer might yell DAMAGE- NO REFUND We'll get to that later.. Better test: FILL the drive and readback.. I found something called testdrive.exe at this site: http://www.schnapp.org/e-britain_ripoff/ He is on a mission to nab fake capacity MP4 players Lots of folks should mirror this file. 2 other guides had good ideas too: Cluzi recommends Barts Test stuff http://www.nu2.nu/bst/ I think these are the folks who put the BART PE test boot cd together great work.. I havent used this, but it sounds a lot like the idea behind testdrive, only more detailed. S_CLARK recommends BMP files and a batch file to name and fill the drive, a good fast suggestion too.. I tried jpgs before I found testdrive.exe So if you get errors after 480- something or 980-something megs on your 4GB drive, you've been burned! What to do now.. Go direct to PAYPAL and lodge a complaint. In mine, I didnt accuse the seller of fraud, but at the same time I insisted that I WAS NOT GOING TO MAIL IT BACK TO HONG KONG FOR EXCHANGE OR REFUND. For one thing, all I might get back is the "purchase price" rather than the heavy shiipping fee. OR, like the PREVIOUS set of 2GB drives, The seller will just "never receive" the return and never answer again, (HI BEUTYZONES!) especially after the paypal dispute time limit is up. DONT LET THEM STRING YOU OUT.. Lodge a dispute and eacalate in 10 days. Do not let the time limits slip by! If worse comes to worse you can offer to send it back AFTER a refund, and if THEY include $3-4 postage.. Remember.. its a fraud, not an error.. This time, I got a full refund in 3 days.. ON the SLIM chance that the seller had been fooled too, I left NO FEEDBACK, good or bad.. SO.. next USB drive and or MP4 player.. even a brand name.. Trust but VERIFY!