The guy's entire record as governor IS conservative (he always anti-gay marriage, and vetoed numerous anti-life legislation).
However, there are two things which gets him in trouble with the skeptics:
1. His pro-choice statements in 1994/2002. Acting pro-life from 2003+ does not do him any good with some skeptics.
2. His signature achievement in health care legislation which the Heritage Foundation designed as the conservative alternative to universal health care.
But if you are opened minded, then look over this think and ask yourself if that is a conservative record or not?
Romney's been solidly in the Republican camp -- note: not always the most conservative camp -- on the vast majority of issues. When he was pro-abortion, he was (sadly) a pretty solid republican who was pro-abortion.