Looks fine in the demo app, see CompListPage -> the List1_Clicked(ItemId As String) event.
Put a log in the Page_ParseEvents to see if the event is raised, but maybe the method signature in your code is wrong:
Sub Page_ParseEvent(Params AsMap)
Dim eventName AsString = Params.Get("eventname")
Dim eventParams() AsString = Regex.Split(",",Params.Get("eventparams"))
Log(" event name: " & eventName & " " & Params) ' <----------------------
...