i had the same problem with advantage... the vet said it has nothing to do with the meds, they're working... it's when you have an infestation of fleas does it get out of control, when that happens, the meds cannot control it. I would suggest wearing a pair of white socks and walking around your house, and next to your lawn. I had an infestation on my lawn that required the spraying of quite a large plot of land. TWICE!! After I had done this, no more fleas on Lola, or on us. If you go outside in your socks and see little black fleas jumping on you, my guess is your infestation is mainly outside, but you're bringing the fleas inside (either you or your pup). Lola had about 20 fleas every time i checked until i fixed the source of the problem and had the OUTSIDE lawn sprayed by a professional. If you do decide to hire somebody, please make sure they have a warantee.. totally worth it. They will come back and spray until not one flea remains... inside and outside your house... just my two cents, and something to think about... its nearly wintertime, and fleas will naturally go into a resting phase... so...
ANyhow, good luck with it all... fleas SUCK!!