I use Frontline Topspot and haven't had a problem. Good thing too, since ticks are almost impossible to see on my black labs. Of course, I don't live in a heavily wooded area which limits the tick exposure as well.
They seem bad in Central MD also. My kid had one on her stomach the other day, luckily it hadn't latched on... We have a wooded lot and I put some bug killer around the residential perimeter of the house. Hopefully that will keep the buggers away from us adults (I don't play in the woods that often.. I need to get in touch with that inner kid again)
When I lived in Saskatchewan we had ticks so bad one year I pulled over 100 of the little buggers off one of my dogs. My other dog didn't have as many, maybe 45 or 55. The species of tick we have is larger than the dear tick so they are easier to find, but they still give me the creeps.
We've already pulled about 5 off our little pug this year as well. We use Frontline, but it hasn't really worked that I can tell. Of course we often nab them before they sink their hooks in, so maybe it is.
We bought some tick pesticide to lay out on the yard. Maybe that will help.