I think that my fit is good. I have the same issue on both my mtn bike and my road bike. I've switched back to platform pedals untill I get more comfortable with this.

I think that this might be more of a mental block than anything else. I was practicing moving slowly with one foot uncliped a few weeks back and took a good slow motion fall. Although I was not seriously hurt, I ended up with a bit of road rash and a nasty, nasty, painful bruise on my butt cheek.

Since that happened, I've been real skiddish. I need to get over this hurdle. I think it is my main sticking point that is preventing me from having fun and progressing.

I guess I'm just frustrated that I can't make myself get past this.