Why are you playing 5-6 feet behind the baseline? While some may play that deep for singles, it might not be the best positioning for doubs. Playing that deep would probably make it more difficult to play short x-court shots to your alley. If you are not going to come to the net, at least get yourself up to the baseline.
If the lobs are still a problem, then have your net guy play a bit more off the net on the troublesome side to discourage lobs. How close is your partner currently playing the net? He should not be closer than the middle of the box (except to attack a ball at the net).
Every tool is a weapon -- if you hold it right. (~Ani DiFranco)