STilly - did you add any soil to your compost? Sometimes, dropping a couple of shovels of garden soil (not compost or peat) in on top of a pile of freshly added refuse or grass clippings will help it to rot down... enzymes in the soil or something.

Maggots tend to prefer rotting meat or faeces so either your compost wasn't as vegetarian as you thought or else you got another larvae altogether... my favourite would be hover fly larvae, otherwise known as rat tailed maggots. They're harmless and do a lot of good with pollination in the garden, but the maggots/larvae do look a bit icky. They like wet/soggy soil so I'd work on improving the drainage in your compost bin before you start to fill it again.

I am at home for a week or so, for various reasons so I really should be doing some sorting of my own... trouble is, I just don't have the energy!

LTS