Is the Mixture broken?

[whoarmongar]

Before the latest patch the mix on spit (back rich) worked ok, switching to lean mix for cruising worked ok till you got above about 16000 then it all went tits upwards , running too rich spluttering vibrating etc.
Now since the last patch I really dont know what the hell is happening with the mix. Taking off I get better acceleration with lean (fwds) mix ?? Before the patch the engine wouldnt even start with wrong mix selected, this is how it should be. Now the engine will start with any mix selected. Rich mix just doesnt seem to be any use , but still at +16000 the mix is far to rich.
I can only speak about the spit, so far I have concentrated on one type of aircraft and will learn the others given time.However this mixture problem seems to be across all aircraft judging by the forum posts, It seems to me to be at the heart of many engine problems people are suffering in this game especially when going for alltitude.