Highlighting the inherent problems of candidate polling months before the first contests, experts released a new New Hampshire poll yesterday but warned that events such as the Iowa caucuses in February could turn the rankings around.

In the new poll conducted by the University of New Hampshire, Vice President Bush and Massachusetts Gov. Michael S. Dukakis are the top presidential choices of New Hampshire Republican and Democratic voters. Among Republicans, Bush has a more than 2-to-1 majority over Senate Minority Leader Robert J. Dole (R-Kan.) and Dukakis holds a nearly 6-to-1 advantage over Jesse L. Jackson, his nearest competitor among the Democrats.

The results are drawn from a telephone survey of 455 Republican voters and 410 Democratic voters conducted Oct. 16-27.

But the growing importance of the Iowa caucuses, just eight days before the New Hampshire primary, holds the potential for turning any current New Hampshire predictions on their ears, pollster David W. Moore said.

Because only a fraction of the supporters of the leading contenders describe themselves as "strong" backers of their choices, Moore said that his survey suggests "that 72 percent of the voters can be influenced fairly easily by some event or occurrence between now and the New Hampshire primary."

As in 1984, that event is likely to be the Iowa caucuses, which have risen in influence to such a degree that they now serve as a screening process for New Hampshire voters, Moore said.

Bush, who won in Iowa in 1980 but lost in New Hampshire, is now considered tied or behind Dole in Iowa. He is assembling a New Hampshire organization this time round that his supporters hope will help if he loses in Iowa.

"Our game plan has been to assume that you lose Iowa . . . {and} that no matter what outside events happen, the people in New Hampshire will choose the vice president," Bush New England regional director Ron Kaufman said.

Among Republicans, the poll showed steady improvement for Bush and Dole since January, but virtually no increase in support for Rep. Jack Kemp (R-N.Y.), who remains the first choice of 7 percent of those surveyed. The rest of the GOP field is at 3 percent.

On the Democratic side, Dukakis' popularity has remained roughly the same (at 52 percent) since last May, while Jackson has gained, going from 2 percent of those polled to 9 percent. Sen. Paul Simon (Ill.) has gone from 1 to 8 percent; Rep. Richard A. Gephardt (Mo.) is the choice of 6 percent while former Arizona governor Bruce Babbitt and Sen. Albert Gore Jr. (Tenn.) gather 3 percent each.

But Moore predicted that a poor Dukakis showing in Iowa could cause the his New Hampshire lead to evaporate.

Charles Baker, Dukakis' New Hampshire state director, said the poll is "a snapshot at the wrong time. There's so much that can happen between now and then."