Pace
I was thinking the same thing as Randy - you are allready at an ~ 600/cal day deficit so even with out a lot of cardio you should be able to loose weight.
I second the suggestion to keep protein high. Also if you have been doing steady pace cardio you may want to switch to a moderate/high scheme. Something like 2 minutes moderate pace, one minute challanging pace, then repeat 2/1/2/1 for your 20-30 minutes. This change of pace during cardio seems to help with fat loss as opposed to simply burning a lot of calories/energy which can come from LBM. Plus it is a little less boring.
Lets see - 5 lbs in four weeks - Trying to fit into that cute outfit for Santa huh? - lol