Hey,
I have the same issue with a landscape lock on the mail app. Though I don't gave a fix, I found that once you unplug your phone from the radio that you can exit out of mail, than double click the home button and x out of mail. It puts it back to normal w/o having to reboot/respring.
I haven't brought it up on the forum yet but I guess if I'm not the only one having the problem, we can assume there are more people that also have the same issue.
Thanks!