After a quick call while I was out and about (read: using mobile data, not over WiFi) the "rate this caller" screen appeared to lock up with a endless "Loading..." progress bar (see pic). After about 30 minutes I decided to quit the app and restart it (now on WiFi). The "rate this caller" screen came up right away. Likely this was just a network glitch.
File this one under:"Have you tried turning it off and on again?"
Thanks for sharing. We'll try to reproduce the problem.