Originally Posted by JSanders
Is this the separator bars in Messages > Menu > Options > General Options > Separators?
Nope - infact, I just tried changing that option to all three options and I don't see a difference any any messages, or the layout/format of the menu.
On your message screen - what is in the upper left corner? Mine is blank with the bluetooth symbol about 1/4th the way over from the left. Typically this should change with each theme.