Navigation Bar splitting over two lines

[Newmo]

Hi folks!
I am an absolute beginner with Zen Cart but have successfully put together (after much Googling and following tutorials!) a site to enable my boss to offer light graffiti paintings for sale.
However, something has gone wrong in the last couple of days and I have been unable to find a solution to it, in spite of much searching. The top navigation bar, which was showing up fine, has suddenly started to split over two lines (please see attached screenshot). I made a small alteration to one of the items in the bar over a week ago and everything was OK after that. Since then, I have made no deliberate changes to it and cannot understand what has gone wrong.
The problem exists in Firefox and Google Chrome, though strangely it is displaying correctly in IE!
I am using V1.5.0. and the Bask Black Template.
The site URL is http://www.mouseonthemove.com
Any help would be much appreciated.
Thank you in advance.

[Newmo]

Hello again folks.
I seem to have resolved this issue myself. It appears that, when I changed the title of one of the links, there was too much text in the new title and the nav bar was overflowing. I went into the CSS stylesheet and reduced the padding for navMainWrapper and navMain ul and everything seems to be displaying fine again.
Hope this may help someone else!

[gjh42]

Thanks for posting the root cause and solution you found:)