I added a check to ensure that we were dealing with an object and that seemed to fix the problem. I realise that this was probably obvious and may already be fixed in your 1.2 code but thought I'd post it anyway. This was in the onSubmit event in the Wiki form.
if (typeof document._Wiki.CookieName == 'object')
{
if(document._Wiki.CookieName.value!='')<br/>
{<br/>
rememberMe(document._Wiki);<br/>
}<br/>
}