That is my EXACT problem. I got that yesterday and still getting the "too many attempts" bull. Does ANYONE have any insight?
One time I logged in several times during the day (on Pulsar, OSX desktop app) and was told that I exceeded my maximum daily log-ins. Not sure if this is the same, but I called Sirius and told them, they reset my log-in count for the day and it was fine.
I know that yesterday on Stern someone called in saying that he was unable to log-in for several hours the day before and Stern said (of course he might not know, I'm just passing on what I heard) that they were testing/upgrading the systems... he speculated probably because of the iPhone app and increased traffic they're expecting.