Strange snapping issue leaves me with mermaids. help

Hi.
I’ve been teaching myself to use blender 2.57 and all was well until i tried to make a couple of legs.

When i want the legs a bit closer together the vertices start smashing together in the middle when they get within a certain distance of each other, creating a mermaids tail instead of human legs.

I thought this was a snapping issue, so i tried turning it off, but this didn’t work.
So maybe i’m just losing myself in blinding frustration and fail to see the obvious solution, or blender has a thing for fish-tailed woman.
Either way. I can’t move on with the project because of this, so can someone help me out before my brand new Imac and office window suffer the consequences?

Thanks in advance.

Hey, RobbieHoen… you must be modeling something using the mirror modifier. Try turning “clipping” off in the mirror modifier panel.

Anim

You made my day.
Much obliged!