A very quick post because I'm in a mad rush. Here are the latest Scottish figures for Westminster voting intention from Angus Reid -
SNP 39% (+3)
Labour 35% (-1)
Conservatives 18% (+5)
Liberal Democrats 5% (-1)
As previously noted, AR's subsamples have more credibility than those of other pollsters, because they seem to be properly weighted and are therefore more stable over time.