Background Image Freaks Out on A:HOVER

[createErrorMsg]

I cannot for the life of me figure out what is happening.
I have a header and nav bar positioned using float:left and margins. Carefully sliced up background images visually merge the two together into an inverted L...basic stuff.

I put links in the nav bar part and gave them a simple a:hover to change the text color and get rid of theunderline. Again, basic stuff.

Only now, suddenly, when ever I mouseover the links, it makes this funky set of lines appear bisecting the navbar. The lines SEEM to appear inline with the link hovered over, but sometimes other links on the page will make the lines appear, too.

It seems like little bits of my background image are being removed, except I'm not swapping background images in the hover.

Any idea what is going on? I'm currently on an old version of IE. Could it just be a browser bug?

[4css]

Hi createErrorMsg,
Do you have your links in the following order?
A:link
A:visited
A:hover
A:active

[createErrorMsg]

Actually, yes.
Since the original post, I've discovered that if I completely close out IE, then reopen the browser and load the page, it doesn't do the line thing anymore. So I figure it's IE's fault.
Thanks, though.