Fraggle,

You do like tough questions,

The few other things you missed were a tight grip, this is possilbly the only other thing causing a slice. Gripping to tight stops the release properly causing you to hold the face open.

Maybe its just a simple alignment problem, When you slice do you then set up further to the left to compensate??????
This is a big mistake just carry on with a straight set-up.

My only advice is to set your ball up on the far left of the tee box for a couple of rounds, this naturally makes you see the shot differently.

Good Luck

Ian.