Whenever im trying to move a vertex inside of a polygon it wont let me move it, and it will set it to one locked location every bloody time. I know im doing something wrong, and it prolly has to do with the shape history (which i dont know how to erase)...

But then when i move the Y axis up slightly (or watever isnt the axis that wont work) it works fine for a little while.

Im trying to construct the Halo Scorpion tank, and the wheels (i suppose thats what they shouldnt be called...) have 6 vertexi (or 12 after extruded), so a rectangle wont cut it for that. So after i extrude one face i delete the edges in the polygon (cause they arent neccesary) and the move tool PMS's everytime....

VERY frustrating. Im sure everyone has run into this problem, just hoping maybe u guys know the solution?