Recently active topics in Pownce tagged with reply

I've been using the Mobile device web address for the past few days and I've notice that I cannot reply to post sent to me by other users. Once I type a message and give it a star grading (or not even) it gives me a red message on the top of the page stating that I should write text in the message bar to be able to post (Which I did). It only happens when I reply, I'm able to post new messages but not reply to others.