Just a lot of random trial and error. Two steps forward one step back.

Now in IE6 menu stays on one line and no wrapping and no resizing, when browser type size changed.

And now in Firefox the menu stays on one line and never wraps.

But when FF browser type size is changed the menu increases/decreases in size.

Understanding the relevant diffs in FF and IE6 is my main issue now.

Some more trial and error to do. And also test in IE7 and Safari and Opera and...

Thanks for all the suggestions.

Woody