Thats a good point. One Veto in 6 years has to be some kind of record. GHWB's signing of the ADA is what pushed me over the edge.. a vague law that became a goldmine for trial lawyers.
For two-term presidents, you have to go back to James Monroe (5th, 1817-1825) who issued only one veto. Thomas Jefferson did not issue any vetoes so it's not an all-time record but in modern times, W's veto record is unprecedented.