Why does firefox display these lines?

[loydchase]

Firefox is displaying these 3 lines around/on some nav bars that i have. they dont display in other browsers.... if you can figure out a way to change the css to git ridd of these that would be preferred(im using FF specific code in css so that wont effect other browsers)

The bars seem to come from the background of the bars.

 

[RavRob]

Sorry m8 but you might be able to get better support if you contact the FF support team. You will find all sort of help in the FF menu.