ProjectMix sticky resisting faders cbs 5


Have recently bought a porjectmix to use with cubase 5, full version…xp pro and win 7 32

All installed ok, but the fader resist changes and sometime get stuck…
have changed leads, used different firewire ports, tested with midiox for dropouts, which there are none, set the projectmix to be hidden to all midi ( recomended) in midi setup and have it set as a Mackie control unit…

Can anybody help

Have removed sysex from the midi filter which has helped but problem persists?