Can your job change your personality type?

The first, most intuitive, and probably correct answer is no. But I have a strange counterexample. Yesterday I took the MBTI again after posting the string of INFP jokes (jokes for which my wife gave me That Look -- but hey, it's not like I wrote them myself).

For years my results indicated an INFP profile. But yesterday they indicated an INFJ profile. Not a big difference, but a difference enough. Interested, and self-interested, I went back and reviewed the hinge questions, those that, before today, I would have answered differently, giving me different results and, ostensibly, marking a shift in personality.

The questions read like this: "Do you tend to choose rather carefully, or somewhat impulsively?" "Does it bother you more having things incomplete, or completed?" "Are you usually rather quick to agree to a time, or reluctant to agree to a time?"

In jobs such as mine (I'm a project manager for a construction company), impulse, incompleteness, and questionable punctuality are not affordable luxuries. And this way I am more demanding of these traits when I am off the clock. I wasn't always that way.

Has this job changed my personality, or has it only changed the way I process information? And is there a difference?