Don Catchpole

Has anyone else here ever used a half.com gift certificate? I got one for my son as a gift and he told me it didn't work so I went into his account and tried it for him. The thing is enough to drive you batty. First I click redeem and it shows up then once I put in a movie or anything else it dissappears saying that it's "in another cart". I dump the cookies and go back and put in movie first then try to use the gc and I get the same message. Seems like it won't work unless the shopping cart is empty. I sent them an email but I know it will be a week until they respond. Any suggestions?