I agree completely, get them out of Mintpal ASAP, and direct new DRK traders to Bter and Bittrex instead, in my opinion.  Bter also pays you a small interest payment for your DRK balance (usually between .3-.45% annually), so even if trading is slow, you will get some small profit in the meantime.  Bittrex has lower volume and no interest bonus, but I do think it's a solid exchange as well.