ME-Sen: No Wind Shaking the Branches in the Pine Tree State

A new Rasmussen poll shows a static Senate race since last month (June 15 in parens):

Tom Allen (D): 42 (42) 
Susan Collins (R, inc): 49 (49)
(MoE: ±4%)

These numbers are identical to last month's, and, when leaners are included, Collins leads by ten points, 53 to 43.  That concerns me, and I certainly hope Tom Allen is running as many ads as possible tying Collins to the unpopular and mistaken war that she supported from the start.  I know that the conventional wisdom is that voters in Maine only start paying attention to politics after Memorial Day.  Last month, Allen's movement in the poll bore that out . . . but what does this month's stagnation mean?