The poll of marginal seat published today seems to miss the point and be something of a throwback to the old two party swingometer last seen to be effective in 1979.
Virtually all the seats show a swing between Tory and labour (interestingly with a lower swing to the Tories in 2009 than in 2008). But in Lib Dem target seats, in particular those seats where the Lib Dems are in a clear second place and the Tories a distant third, they are still working out Tory - Labour swings.
If this poll is to be believed, they think there will be not one gain made by the Lib Dems from Labour. Considering that the Lib Dems made limited gains from Labour in 2005 with Labour much higher in the polls in the Lib Dems slightly lower, this shows this poll is wide of the mark.
Take a look for yourself here.