can't add more than one feed

hi, i added my first feed. then i created an account from the confirmation email. now i can't add any more feeds. when i try to add a new feed from feedmyinbox.com, the following page loads blank and the feed is not added to my account: http://www.feedmyinbox.com/feeds/subs.... i'm using firefox mac 3.0. i've tried safari and the bookmarklet. both without luck.