I started getting the -403 error again yesterday while trying to get songs. This is also in the US. I wonder if they are doing something to the servers? Another baseless rumor we could start?
edesign: are you running any intensive bandwidth stuff in the background? Sometimes if I am running a torrent then I get that 502 error occasionally when I try to access and preview some songs, and I think it is what messed me up yesterday when buying.
Edit: Need to read more when I post. This may not be your problem unless you have something really intensive happening in the background. Might be worth a check, otherwise the store is probably just messed up or overloaded right now.
Jim