background blink problem

Few days finished with new website. Finally it is W3C and I am proud of it
:)

http://www.car-4-me.com

Problem that I have on all pages is on "on mouse over" when I am trying to
change button background.

It works OK in FF but in IE I couldn't fix it.

Any idea how to fix that "blinking" problem?

Thanks,
Nikola Mitic
http://www.car-4-me.com