Flea breeders

Last summer Sam became infested in fleas. I think the fleas came from my boyfriends dog, but we wont name names. I took Sam to the vet and they gave him a pill that would kill all the fleas on him at that time (we picked up over 200) and then we started him on Advantage. I was assured the fleas would be gone in 6 weeks and that the house would be flea-free. I brought him home and shut him in the kitchen for the day so I could wash and clean everything to rid my house of any flea eggs, etc. I steamed the furniture, the area rugs, mattresses, washed everything that was cloth in the house in hot water including the drapes, placemats, and tablecloths, and all the clothing that isn't kept in an airtight container. We also did the same for my boyfriend's dog and his house as well. I thought I maybe went a bit overboard, but evidently not.

When Sally came here, she was also given this pill (just to be sure the vet told me) and no fleas were found on her. I brushed Sam last nite and pulled off 2 BIG fleas. They looked to be adult which means they probably have families somewhere around here. Is there anything else I can do, or maybe something I didnt do to cause them to still be around? I'm just really irritated that it's the dead of winter here and we have fleas, which means come summer time we will be overrun.

~I apologize for the ammount of typos in this but my 4 year old dropped a cup of Kool-Aid on my keyboard and the keys are still sticking~