I have a label component that is set up to be editable on a single click, - and I noticed that under Android any attempt to input a capital letter just hides the keyboard.
Also cannot input characters like @, !, ?. Each time you try to type it, Label::textEditorFocusLost gets called.
Tested with one of the latest revisions of JUCE (by Apr 22, 2015), reproduced on Nexus 7 and Lenovo p780.