Had a Class A misdemeanor dismissed but is it limiting my jobs opportunities?

Sold alcohol to a minor during a TABC sting, I signed some paper and given some numbers to call to set a court date. When I would call the courts they would tell me they had no record of it. I called for about 3 months and everyone told me it I must have been given a warning so I dropped it. One year later I get a new job no problem and had a background check every year for 4 yrs, still no problem. In 2009 (5 yrs after the incident) I was pulled over for not wearing my seatbelt and suddenly I find out there was a warrant; I had it dismissed and did a few months of probation but all of a sudden I'm having a really hard time finding a new job. My interviews always go great but the day I give them my info to get me started I never get a call back or even a real answer as to why. Its beyond frustrating but what on earth can I do to fix this?