Titanium Studio, build: 126.96.36.199311160316
Mac OS X 10.8.4
Open the Preferences dialog.
Click on either General > Appearance or Titanium > Themes.
Receive the following error: "The currently displayed page contains invalid values." (See first screen shot.)
Try to click on the same items again (may need to click off the item first) and the Preference page displays an empty drop-down. (See second and third screen shot.)