Lee Sykes of DNN Creative informed me this morning that there is an issue with modules that dynamically change the title.

Line 50 in CDefault.vb is commented out:

'Public Title As String = ""

This will cause many modules that use this property of CDefault to dynamically set the page title to break.

Source

I know this will cause some errors. I have several modules that alter the page title based on content for search engine optimization. This will definitley delay any upgrade we do from DNN 3 to DNN 4 in our production environment if it takes longer than 1 month for the next patch/release. I will post any updates here.