I had the same prolem with TDA. They stated that a third party which they use to review stocks said KATX had some questionable aspects so in order to buy you have to phone in the order. I tried to inquire who they were using and what the flags were that the party came across. I got a long winded explaination that amounted to "I don't know." Thats TDA for you.
Does anyone have a broker that is good to deal with when penny stocks are involved?