I was about to write that Romney's 21% is the highest I've seen him poll anywhere (outside of Utah), but then noticed the strange wording of the poll questions. The only Democrats they list are Clinton, Edwards, and Obama, and the only Republicans they list are Giuliani, McCain, and Romney. The poll respondent has the option of choosing "other Democrat" or "other Republican", but still, this wording makes it likely that the respondent will choose one of the three named Democrats or three named Republicans.
Presumably, that's why this poll shows a bigger vote share for both Clinton and Romney than previous NH polls. the people who would have otherwise gone to someone else went to them in disproportionate numbers.
Yeah good find.