Sometimes when you update a bower component, you'll be asked which version of a library you need to use. It will say something like
1) angular 1.3.7 is required by ionic.js but resolved to 1.4.0
2) angular 1.4.0 is required by ui-router but resolved to 1.4.0
....
please choose which version:
And what is happening is sometimes bower components require angular or another library, and you need to make sure you have the correct one installed.
It can be a tedious process at first. I remember I broke an app by upgrading and spent a few hours tracking down library versions or what not.
The best way to do it sometimes is to delete your bower_components folder and run bower install again. Just make sure your main bower.json is updated and has all the correct bower_components. Bower install will look at that file to check what to install.
Hope that helps with the mystery 
and glad you got it working