Horizontal lines won't insert into full margins set in a doc.

[rec]

I am trying to insert horizontal lines in word 2007 and sometimes they only insert a partial line, not from the left margin to the full end of the right margin. Also when I get the partial horizontal line it won't let me delete it.
On top of all that aggravation it sometimes fills in an automatic border. I have gone into Word Options to the Auto Format tab and made sure that Border lines is not checked. I am coming to the conclusion that this technology is very flawed.