Problems with docking station

 

Im using a dell inspiron 1520 dual core laptop on windows 8

i formatted the drive's ntfs and im moving data (mp3, doc, txt, jpeg, bin, iso) from one seagate 1.5 tb external hard drive to the HDD 3.5 sata WD 160gb in the win star docking station using usb 2.0 http://www.win-star.com/eshop/goods.php?id=81

The files move over slowly but then stop and says cant locate hard drive location half way during transfer, i have to skip the rest of the files. in my computer and in disk management you can see and still access the drive if windows explorer don't freeze.
is it the hdd (i have tried 3 WD HDD's)? transfer cable? or the dock? if i move file one at a time is ok but if i move large amount of folders/gb's at a time it stops. or windows explorer freeze and i have to restart explorer starting over again.
also while formatting drive it wouldn't find the disk i had to turn off and put on the dock and it would format fine after?

thank you for reading and any help would be appreciated

Many Thanks
T.J