I have a VERY interesting problem with DNN 3.3.5.  First of all it is NOT possible for me to upgrade to any other version for this particular site.

I have a module that right now is REALLY simple, only two view controls.  The first one has a hyperlink that is set to navigate to the other using

NavigateURL("ControlName") where "ControlName" is the name of my second control.

Now, when I click on the link I just get a blank page, the module is not rendered but there is also not an error.  Nothing is recorded in the Log Viewer either..

Have you tried putting in a break point to see what exactly is the value of NavigateURL("ControlName") at runtime?  Is the value what it suppose to be?

By blank page, do you mean an absolutely blank page or is the skin and other modules, etc. showing? When you say "ControlName" is the name of your second control, am I correct to assume thay you mean the ControlKey for the second control.  Has the second control been set up in ModuleDefinitions with this ControlKey. What is the ControlType of the second control - View, Edit, Admin, etc.? Are their controls that would visibly render even if a databound control (DatagGrid, GridView, etc.) is not being bound or its datasource is coming up empty? Have you tested (breakpoint or Response.Write) that the Page_Load handler of the second control is getting fired?