Thank you.
Again, I cannot reproduce the problem. All my tests show that everything is fine, as with the other problem you reported earlier (market creation). When I set the fee to zero, no fees are applied, and when I select the max amount to transact, this works for me.
Something is very strange and I have to think of how to debug it. I am not sure right now what other information to ask you, once I do I will get back to you.