Assuming that is an external webpage, it is still tracked.
The way the URL and page name are captured are sligthly different from Marketo landing pages and that may clarify why smart lists are not reflecting the activity.
Assuming a page
Marketo would record the external page as
Webpage URL: my_external_page
Query Parameters: tracking=MunchkinAPI&test=001
Referrer URL: http://localhost/test1.html
where my_external_page was the name I provided in the Munchkin API's function, called as
<s c r i p t src="http://munchkin.marketo.net/munchkin.js" type="text/javascript"></s c r i p t>
<s c r i p t>
mktoMunchkin("000-000-000");
mktoMunchkinFunction('visitWebPage', {
url: 'my_external_page', params: 'tracking=MunchkinAPI&test=001'
});
The default tracking works as well. Marketo will capture the URL and optional query parameters.
*** Please note "script" is a single word without spaces. I have added spaces to avoid the system interpreting as tag ***