Unless it is included in the Toolbox or the themer states that is specifically made for 1.5, do not use it.
While the framework-res and the Services.jar were not significantly changed in this release (most of the framework work went into the framework.jar) the apps were all rebuilt..
So you will break fixes that were introduced in Liberty 1.5 like Exchange and Mms...
the Apps were all rebuilt for a reason please do not undo that work so you can run an older theme!!!
If you must have a theme from Liberty 1.0 the stay on Liberty 1.0 until the themer makes an update.
