Can't receive WhisperPush Messages on CM11

My Phone runs CyanogenMod 11. I registered in [WhisperPush](https://github.com/CyanogenMod/android_external_whispersystems_WhisperPush) via the Settingsentry and got the verification code. I do have a Google Account, the phone is new and I haven't installed any apps yet. Now I wanted to text with my contact (he's using [TextSecure](http://www.appbrain.com/app/org.thoughtcrime.securesms)) via WhisperPush/TextSecure. When he sends me a message using TextSecure, it's shown to him that it's sent encrypted, but I won't receive any message at all. On the other hand, when I send a message, it's send as a normal text without any encryption at all. I tried to enter the verification code somewhere, but can't find anything, permissions should be also fine, at least I allow WhisperPush everything. How can I get WhisperPush to work? Hint: WhisperPush is [integrated with CyanogenMod](http://www.cyanogenmod.org/blog/whisperpush-secure-messaging-integration) , so *Google Cloud Messaging* shouldn't be involved. Update: I tried it with another contact, who uses TextSecure as well. While I still won't get any encrypted message and the messages I send are still plain text, after unregistering and re-registering from WhisperPush I noticed that I've the public key of my contact in my list, he had mine as well. So it seems there was a key-exchange, but somehow the messaging app(?) doesn't know it can communicate with this contact using WhisperPush/TextSecure. Update II: I just installed the TextSecure (now Signal) app from the Google Play Store. Works flawless.