recurrent flea problem

Question
I adopted a stray (mixed breed, probably mainly border terrier).  She came with fleas and ticks.  She lived outdoors in South Carolina.  I have treated her with Frontline and Capstar - neither of these appears to have diminished the # of fleas.  Please note that I treated her with Frontline a month ago for the same problem, and they did seem to disappear then, but came back a month later.  Can the fleas be resistant?  Shouldn't I see some improvement in the day or two following treatment if they are sensitive to the medicine?  Why wouldn't Capstar have worked, since this was the first time I gave it to her?  She also has been bathed.  I live in a 7000 sq foot house.  It is very hard to clean every square inch, including beneath furniture, etc.  Do I need an exterminator?  What is a 'flea bomb'?  I have children, as well - I don't want treatment which will be harmful to them.  Thanks!

Answer
If the Caspatar anf FRontline are not doing the trick, then there is an overwhelming flea population in the environmnet. Fleas are not resistant.  I would call an exterminator and make sure that they do the yard as well as the house.  Repeat the treatment in 3-4 weeks.