When copying across a folder containing various files from my Mac book Pro to an external hard disk, half way through the operation a box comes up saying "The operation can't be completed because an item with the name XXXXXXXX already exsists".

System is running on MAC OSX 10.6.8

I can copy the same folder across from a PC to the same hard disk without any issue. I have even tried a different hard disk and USB stick with the MAc book also the same problem occurs...

Can anyone help me reoslve this one ??

Mobile Hard disks are formatted in MS-DOS (FAT)