This poll was already debunked on another thread. When both Perry and Palin were included, Romney was in front (and Palin was ahead of Perry). But then they took Palin out and kept Perry in in order to get the ‘Bachmann leads’ result.
Further, if you read the actual poll, you see that Bachmann and, to a lesser degree, the other early-alphabet candidates (Cain, Gringrich and Huntsman) benefited by listing in alphabetical order, rather than rotated listings, which is good polling policy.
Also, this was an attempted hit poll on Palin and plumping up poll for Bachmann, with the positive question of who they’d vote for if it came down to Romney and Bachmann asked, along with negative questions about Palin, such as whether they thought she hurt the GOP image (respondents at the start of the poll had actually given Palin the highest positive rating out of any of the candidates) and whether they wanted her to run. (What a shock, a fair percentage of those backing other candidates didn’t want Palin in the race!)