I just got a 32GB USB Drive but can't copy more than a few GB on to it.

Tried as FAT32 and NTFS

It actually looks like I can copy the files but when I try to open them they are invalid.

I tried a 4.5GB zip and it worked fine so I'm thinking its the number of files? i.e the device can only handle a set number of files on it.

Anyone heard of this before. Whenever I search I find lots of people having the issue of transferring large files but not lots of small ones.