The first time it happened it was temp and I told them I was just on vacation so they unblocked it. I was fine for a time using my app on my phone to trade but then stupid me started doing it again from trade architect.
I asked if it was a Penson rule or Ameritrade and the guy told me Ameritrade just came out with some new funky rules and getting a lot of complaints. It's a shame as I really like them and negotiated a lot lower commission with them than the standard.
They said they'd be happy to remove the block when I came back and gave them a call but I'll be going back and forth so that won't do at all.