My lid doesn't fit snugly to the point where no steam gets out. It does let steam out - I get moisture beuildup aroudn the edge of the lid and it vents out itself and makes the lid rattle a little when it does. I don't know if this is normal or not but it has always done this.

Maybe try more fluid or even using a little spray oil or similar on the bowl as this may prevent it sticking quite so much and decrease the burning.

What colour is your bowl? I am sure that I had a discussion with BG at some stage (the lucky girl has two SCs) and she said that the one with the white bowl didn't burn as much as the one with the black bowl (or at least that is what I remember - I can't find the post this second). My bowl is black and does burn occasionally - I find that it is usually when I have had it on the low setting and been cookign it for a long time - it doesn't happen when I cook on high for 4 hours like a lot of my recipes say but if I cook on low for 8 hours it does tend to burn more often.