hey guys... ived been using maya abit over a year now and i dont know if its my maya or it happends to everyone else ... well it Sirtenly doesnt happen in the maya tutorials which i watch.

well the problem here is that when i use the "extrude face or edge" tool, i always seem to get an extra vertex at the end if you get what i mean. is this ment to happen in maya or is there a setting in my polygon options which is on default or something?
when i move the middle vertex, there seems to be another one behind it.

heres a picture ...
i always get this but i just have to merge all the vertex's up but it takes too long when im doing a mouth and that when theres soo many..
(sorry about the image size)