changing height of top menu bar throws layout off

Hello,

Posting here with an odd situation...

I'm modifying the layout of the ZenCart template for a website I'm putting together and am stuck on something that makes no sense to me.

I have set a repeating background image for the header menu and, having found that the default height (set to 1% in the css) is too tall and throws things off vertically, decided to set it to match the actual height of the image, which is 21px. However, when I view the page after making that change the content beneath the header is shifted to the right by about 20 pixels.

I'm not changing the width of anything. Only changing the height of 1% to 21px. Very odd.

Has someone figured out why this is happening, or perhaps have suggestions for a fix?

Thanks!

With endless different template layouts it helps if you can post a url to what your looking at , it helps to visualize sometimes.

If you don't want it spidered just yet , post it with spaces in or the word "dot"