Thanks Valtam for the edit 
Wasn't sure how to go about that.
Gold_finger, thanks for that info too, about marking as solved and creating the new partition table.
I hadn't tried making a new partition table, I only reformatted.
Making a new partition table before formatting made no difference to the performance of the USB's.
They are both faulty as the testing results of the 2nd device (below) are nearly identical to the first one's results.
A few hours ago we went onto e-bay to sort it out & the seller's account had been removed so I guess we weren't the only ones having problems with these devices.
Thanks to all for your help 8)
The media is likely to be defective.
6.9 GByte OK (14494182 sectors)
55.5 GByte DATA LOST (116543002 sectors)
Details:4 KByte overwritten (8 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
55.5 GByte corrupted (116542994 sectors)
4 KByte aliased memory (8 sectors)
First error at offset: 0x00000000104c1000
Expected: 0x00000000104c1000
Found: 0x29b4a100cf4d1000
H2testw version 1.3
Writing speed: 17.5 MByte/s
Reading speed: 7.16 MByte/s
H2testw v1.4
EDIT: Handy little testing utility that H2testw is, no install needed runs from the .exe if you have WINE.
When it starts it'll be in Deutsch, just click the English button.
Format your USB Drive/Memory Card/whatever, mount it, open H2testw, click Select Target, navigate to the drive you want to check, 'all available space' does the whole drive or you can select a smaller amount and set it manually, then just click Write + Verify.
It'll take a while, took over 3 hours to do 64 GB USB drives, once finished click the "Copy to Clipboard" button to save the report.
Website is here - http://www.heise.de/download/h2testw.html Deutsch site.
I found it here - http://www.portablefreeware.com/?id=1519
Wasn't sure how to go about that.
Gold_finger, thanks for that info too, about marking as solved and creating the new partition table.
I hadn't tried making a new partition table, I only reformatted.
Making a new partition table before formatting made no difference to the performance of the USB's.
They are both faulty as the testing results of the 2nd device (below) are nearly identical to the first one's results.
A few hours ago we went onto e-bay to sort it out & the seller's account had been removed so I guess we weren't the only ones having problems with these devices.
Thanks to all for your help 8)
The media is likely to be defective.
6.9 GByte OK (14494182 sectors)
55.5 GByte DATA LOST (116543002 sectors)
Details:4 KByte overwritten (8 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
55.5 GByte corrupted (116542994 sectors)
4 KByte aliased memory (8 sectors)
First error at offset: 0x00000000104c1000
Expected: 0x00000000104c1000
Found: 0x29b4a100cf4d1000
H2testw version 1.3
Writing speed: 17.5 MByte/s
Reading speed: 7.16 MByte/s
H2testw v1.4
EDIT: Handy little testing utility that H2testw is, no install needed runs from the .exe if you have WINE.
When it starts it'll be in Deutsch, just click the English button.
Format your USB Drive/Memory Card/whatever, mount it, open H2testw, click Select Target, navigate to the drive you want to check, 'all available space' does the whole drive or you can select a smaller amount and set it manually, then just click Write + Verify.
It'll take a while, took over 3 hours to do 64 GB USB drives, once finished click the "Copy to Clipboard" button to save the report.
Website is here - http://www.heise.de/download/h2testw.html Deutsch site.
I found it here - http://www.portablefreeware.com/?id=1519