I had the same problem when using community compost. I don't think they compost it long enough or to a high enough temp to kill the weed seed. It took about 3 years to get rid of the new weeds. I just kept pulling and pulling and mulching. Try laying down some black and white newsprint to help control the weeds also. Persistance is the best bet against weeds. Don't let them get the best of you!!

I cut a sponge into 2 pieces, rubberbanded them to the ends of tongs, and dip that into Roundup to coat just the plants I want. You will need to be persistent. Oh, and avoid doing on windy days, volatiles can drift over to the "good" plants! Also, some people use a paint brush instead.

HTH

Oh- here and I thought you were lookin for more weeds- I was going to tell you to come on over and help yourself to as many as you would like!