Hi Louise. If you're still having this problem, would you mind posting your html code? One possibility that occurs to me is that the new skip feature you added might have been coded using a new version of html, html5. Most of the latest browsers would recognize the code, but MediaLab doesn't yet accept html5 in custom items.

If this does turn out to be the problem, it might be possible to simply re-code the same command in html4.

I hope this helps!