Windows explorer hangs up

[saw]

I recently bought an external DVD for backup purposes. Now I find that when copying files back onto my hard drive, explorer hangs up.

This happens on both my notebook and desktop running XP (SP2) and Windows Me.

Could this be to do with not finalising the DVD. If so how do I finalise a disk? I cannot find this option in Ulead Burn.Now software.

Any tips anyone?

Stephen