OK this is really embarrassing but I really don't want to miss tomorrow mornings ride so help me out if I am doing something wrong. If nothing else, venting may help keeping me from going insane tonight...

So I got a flat (rear wheel) on my last ride. It was very close to home so I limper home and postpone it until today to change the flat.

Its getting late so I quickly change the flat. I put the wheel back on. I turn on the mini compressor to fill the tire up while I tidy up some mess in the garage. The tire blows up. It scares the bejeebus out of me. It scares the bejeebus out of my wife.

Well, what can you do? Maybe the tube got pinched while I was in a hurry. So I change the blown tube again. Veeeery careful to check that there's nothing protruding from the tire, that the tube is completely seated in the tire etc. I pump it up in stages: first up to 40 PSI So far so good. then to 115PSI (I usually ride at 120). So far so good. I pump up the front as well and I think may be I go for a quick spin around the driveway... And then BAAAM the back tube blows up again!!!

I've been swearing in 6 languages for half an hour but I still wanna ride tomorrow morning and I have only one more spare tube left.

What can I possibly be doing wrong? I am no Shelden Brown (RIP) but I've easily changed a dozen tires over the last year, often on the road with no such problem ever. Should I go to the LBS and rip him a new one that the tubes he sold me are defective?

HELP!!!