Bicycle Mechanics - Repeated flat tires

I have been having a small problem with flat tires lately. I've had my bike for about a year and about 2 weeks ago I got a flat in the rear tire. I don't have a lot of experience (ie. skills and knowledge) in replacing the tube so I took it to the bike shop near my house. Then yesterday I was riding and got another flat when I bunnyhopped over a small pothole. Went to the bike shop today and got a new tube installed, and then less than 2 hours later I'm on a ride and I get a flat when I went on a small bump in the road (less than half an inch high).

So what I want to know is if anyone has any experience with this or any ideas about what's causing this. <http://www.opusbike.com/site_route_10.php?lang=en> My bike is the Fidelio under the cyclosport tab. At first I thought that maybe my tires were overinflated but I ruled that out pretty quickly as I keep both my tires at 100psi and don't think that should be the problem. My other guess is that the bike store I go to is using very low quality tubes. But either way I would love to hear some thoughts on this.

Tube quality very rarely has anything to do with repeated flats (I've only experienced it once when a bike shop apparently got a bad batch of normally good quality tubes)

knowing the position of the hole in the tube goes a long way towards figuring out what it might be...
outside of the tube, Have the shop remove the tire and flex it inside out and inspect carefully for anything poking through... it could be just below the surface when the tire is in a normal position, but the flexing from a bunny hop or bump could be causing it to protrude into the tube and puncture it.
Also make sure that the tire isn't worn... as the tread wears down you'll have more flats.

inside of the tube inspect the rim and rim tape

if it's two holes that look like a snake bite, it's most commonly caused by low tire pressure.

When you're searching inside the tube, flex that thing all over the place, and really rub your fingers into the rubber. A strand of braided brake cable wire can be almost invisible.

Also, like mclaughlin said- if your tire is worn, its simply going to be more susceptible to punctures. Worn rear tires will have a flat stripe all the way around in the center of the tread.

I wish bike shops patched troubled tubes, rather than just replacing them- tossing out the old tube discards the evidence needed diagnose future problems.

I'll give the tire a check, I think it's very possible there is something protruding inside. As far as wear is concerned the tire is in excellent condition and I don't think that is an issue.