Kontrol Z1 sound dropouts (Traktor iPhone)

Past few days I've been having some troubles using the Traktor DJ for iPhone 4 together with my Kontrol Z1 mixer.

Note that I hadn''t updated neither iOs or the app itself when the following happened.

Three or four days ago, when I opened up the app on my iPhone, I was shown a video which I think I remember from around the time 3 new FX effects were released (iceverb, transpose etc.).

Ever since I was shown this video, the app doesn't work with my Kontrol Z1 mixer anymore. A few problems I'm facing:
-The app had to re-analyse my whole music library, even though all of it was analysed before (everything is analysed again by now though)
-I can't load new tracks when my phone is still plugged into the Z1
-If I even glance at the Z1, the audio drops out, let alone touch a knob.
-Sometimes audio will only play for 1/4th of a beat and then drop out completely
-It's impossible to play 2 tracks at the same time, the audio simply drops out
-The 3 FX effects (iceverb etc.) have disappeared and restoring in-app purchases doesn't help

Since this started happening, I've tried to update both the app (1.6.2.849) and iOs (7.1.2) to the latest version and free up more space on my phone (5GB+ free space). I can now manage to play one track as long as I don't touch anything, but it's pretty much broken and totally unusable to properly mix otherwise.

Am I the only one who randomly was shown this video upon opening the app last week (without any kind of update), lose 3 FX effects and the ability to use the app with the Kontrol Z1?

Any help or advice would be much appreciated.

 

I saw your comment regarding no update ... but still I have my concerns that a iPhone 4 with TDJ 1.6 will work at all, see here: maybe helps): http://www.native-instruments.com/forum/threads/4s-iphone-is-crashing-traktor-dj-app.233798/