A question to __autoload() fanboys

Hi, Since the flame [1] about the evil QuickForm developers not willing to fix the bugs in other peoples's code [2] somehow died down I'd like to ask a new technical question. I was going through QuickForm thinking on whether to actually fix the "bug" #3197 and found a following code fragment in HTML_QuickForm_Renderer_ITStatic::_getTplBlock():

        if (is_a($this->_tpl, 'html_template_sigma')) {
            ... code for HTML_Template_Sigma ...
        } else {
            ... code for HTML_Template_IT ...
        }

OK, I *can* fix the case of 'html_template_sigma' here, but the problem is the following: if a person uses HTML_Template_IT package he most probably does not have HTML_Template_Sigma installed (and vice versa), thus trying to autoload the class will fail! How should I fix this problem? Scott, what will you suggest *this time*? [1] http://marc.theaimsgroup.com/?l=pear-dev&m=112239979300570&w=2 [2] http://pear.php.net/bugs/bug.php?id=3197