This is a discussion topic that comes up periodically on this board. Many posters on this board believe that our Chill is attributed to the Penson issue.
After the Chill, I was restricted from buying anymore in my TDA account, so I added an E*Trade account for my penny trades since the Penson issue doesn't exist there. There are several other Brokers that have already been suggested by others that are great in this regard as well.