They forgot to mention in the update walkthrough that leaving the test mode folder on the sd card keeps booting you into windows ce.
I used this to copy and back up my f90bt's file system onto my sd card.
Hopefully I'll be able to figure out why my TTS doesn't work, as well as maybe figure out where the graphic icons lay so I can stick my car onto the GPS map. Other more adventureous members with CE experience might want to poke around further.