[This one happens on Windows]
Create a mobile-web project (with Titanium SDK 2.0).
Right click to run the 'Titanium Mobile Web Previewer'.
An internal browser is opened, but the page is blank.
Right-clicking and viewing the source shows lot of code there, so we have the content, yet it's not rendering.
Selecting the launch (via the Run configurations) and editing it to run on external browser works fine.