Ok,
I have sorted the issue, the cams are running smooth and no jitter or jerky streams, it was nothing to do with motion or res settings, but something i overlooked.
.....in the settings of the Tiandy TC-R3880, under network card there is a setting called "Polymerization Option" which was set to "load balancing", which is what the Qihan NVR was set, but this Tiandy does not behave the same way, so i have set to "multi-access" which has solved the issues i was having, plus i have replaced many faulty Qihan NV534DO-P ipc's, and all is good.
Side note: this Tiandy 80ch works fine !