I deleted all the contents of the "assets" folder, as there were too many files no longer used in the project, figuring out Titanium would copy the required files from the "Resources" folder automatically. But not so.
The "assets" folder remains empty. And compiled app when run on a phone force closes.
I wonder if there is there a way to "rebuild" the project?
EDIT: never mind, changing project options forced it to rebuild
Yes, touching the tiapp.xml file will force a full rebuild of your project.