According to the Washington Post, at leat three GOP electors have sated they may not cast their votes for Romney if he carries their state.
http://www.washingtonpost.com/...
Its not huge but it does pose a problem. If the map shifts in Nevada or Iowa, you may be short an elector. Romney will win Texas, but he may need to subtract 1 elector from his precious but considerably smaller list of locked in Electoral College votes for his candidacy.
The bigger problem is that the failure of Romney to assauge the Ron Paul camp will give his party dispepsia after election day. If Romney loses (and its likely he will), Ron Paul will likely get more than three Electoral votes) and the rift among Religious Conservatives, the GOP establishment and the small but very activist GOP libertarian camp to break wide open.