Unable to Cut & Paste (move) files between drives

It started after I installed a new WD Caviar Blue 320GB SATA-II 16MB drive, after which I installed a fresh copy of XP SP2 on the drive which I use as my system drive which is a Seagate Barracuda 7200.10 160GB SATA-II 8MB drive.

Initially I though it might be an issue between these 2 drives, but I am not able to move any files from/to my external Seagate 250GB drive which I've been using almost a year now.

When I try to move something, it's as if the process pauses or waits for something, because it seems to be running in the background and if I try to restart or shut down, I get a message saying that I have to wait for it to finish. But nothing happens...
And if I try to copy the same file again, access is denied because "another application is using the file"...

I've scanned for any signs of a virus/spyware/malware, etc and everything is clean. I did another install of Windows on the 320GB, but still the same result.

BIOS is updated and there aren't any issues with the RAM. In the BIOS I've disabled IDE Prefetch Mode, which I thought could make a difference, but to no avail.

Funny enough, I don't have this issue when I just do normal copying.

Any ideas? Or am I missing something?

Gave it a try, but still the same issue. I re-partitioned and formatted both drives with NTFS before installation.

It seems now like it could be a hardware related issue.

I've got a Gigabyte M57SLI motherboard that seems to be causing the issue, because I've tested memory and swapped SATA cable.

Actually running out of ideas that could be the possible cause...
Any suggestions would be welcome.

Thanks for the help so far