How to fix "Error 3259" on iTunes when downloading large(r) files.?

I have tried to buy Inception and the first Pirates of the Caribbean through iTunes on BOTH my Mac OS X and Windows 7, but both times, I got error 3259, and the download didn't work. I can get songs and even TV shows, but never movies. Both times I have had to contact apple to get a refund, and they can't seem to give me a straight answer about how to solve the problem. In case this is relevant, the 2GB movies never even start downloading. They can't download a single kilobyte, while the 1.25 GB TV shows do it without a problem.