[CSS] width not working right in mozilla

Well it sin’t woking for links at least, I have gone further and added int he min-width the attempt and improve this, but it is still broken. basically, I have this code for my links:

.menu .section .nav a{
  margin-bottom: 1px;
  padding-left: 15px;
  background: url(images/a_off.png) top left no-repeat transparent;
  text-decoration: none;
  min-width: 168px;
  min-height: 20px;
  width: 168px;
  height: 20px;
  color: #999;
}
.menu .section .nav a:hover{
  margin-bottom: 1px;
  padding-left: 15px;
  background: url(images/a_on.png) top left no-repeat transparent;
  text-decoration: none;
  min-width: 168px;
  min-height: 20px;
  width: 168px;
  height: 20px;
  color: #0066AA;
}

and am wanting to be able to see the full background image in the background, not allow mozilla to break off the link directly after the text, as it wants to do.

Here is a screen shot of what it currently looks like in mozilla, then what it should look like (works in IE)

Normally I don’t worry about link backgrounds due to the problems I have had in the past, but this client wants to have their links in the navigation bar with the background, so I must find a way.