[jQuery] Form Ripping

Anybody know why this jQuery code only shows the fieldsets I wrap
round it for a fraction of a second before vanishing? Click the Go
button several times quickly to see the fieldsets appear.
http://styledna.net/jform/
Basically im trying to grab in all form elements then wrap them in a
fieldset for each form. Just doesnt seem to work unless I add in an
alert(), in which case it works fine...