I'm using exactly the same code as posted on the website and don't experience any problem in Firefox (3.6.5 on Mac)
As for the problems concerning IE you may want to have a look at the comments on the developer's websitehttp://www.phatfusion.net/plugins/imagemenu/
I spent a while puzzling over this and perhaps it will help some of you…
The menu would load fine locally, but when added to a live webserver it failed. I called my html page sample.html.
I receive the following two errors :
(These errors come up in IE, FireFox does not even tell you it has an issue, but also does not show the menu)
Message: ‘ImageMenu’ is undefined
Message: Object doesn’t support this property or method
I finally got around this thanks to some of the comments above where I saw a remark about linux servers being picky about case sensitive code. I opened up all the CSS files, along with the js file and the html file I was using in Notepad++ and did a “Find in all opened documents” for imageMenu. I then did a find a replace to make them all lowercase imagemenu and this sorted the issue.
So maybe replacing imageMenu
everywhere fixes the problem for IE.
Of course Notepad is a Windows application but if you're on a Mac use TextWrangler to open the files and do the find&replace (or use MassReplaceIt find imageMenu replace imagemenu which should work too).
I didn't try that fix since first I have no access to IE to see whether it works or not and second if something works in Safari and Firefox for me it's enough (since IE really is a pain for the world I don't mind about it anymore).