Page URLs and permalink question.

I have trashed my pay and checkout pages.Every new one has -3 or ascending number behind it. I am trying to simply have it say Checkout and not the revision I am doing. I think this maybe a bug in why my shop dont work.
Also when I try to change my permalinks to custom and add /%postname%/ on the bottom line it saves it but always kicks it up to the post name option after saving. Any help would be great! thanks