Elektron Musical Instruments

hi,
yesterday my SFX-60 arrived.
I love the sound and the possibilities.
Another Elektron classic!
Only problem sofar is that i get a strange release behaviour with some of the sounds.
When i lift the finger of a key the pitch of the note drops to a different pitch and stays 
there for a while.
I can reduce it with the AMP section but then i get a really short sound.
Is there a trick to have a full sustain without that releasebehaviour?

Whats even more strange is that no matter what key i play the notes will all drop to 
the same pitch!

Any idea what i am doing wrong?
I am using my V-Synth on channel 9 with the Autochannel function.

thanks
Hans