I'm on a Lumia 925 and developer preview - this morning a strange thing happened...
When I open any messenger of any sort, and start to type, the keyboard pops up and allows me to write one word only before refusing to accept any more inputs (they keys show 'pressed') - only way to write another word is to close the keyboard and pop it up again.
Massively annoying - can't find anything on it anywhere! Help!