Angular and Scope - or - How not to waste time figuring out why a scope value is not 'working'
The creator of Angular notes it in this video which is well worth the watch.
Basically when using includes or directives etc you may not be getting a scope value as easily because it is child scope and you may be looking in the parent scope.
For example This include if I have an include and it references a model attribute like this
//Some include
<input ng-model="firstname">
I may not get the results from that input that I expect.