Animation different in Render

I’m not sure if this is a animation or render question so soz if its the wrong section.
Basically when i play back my animation it looks fine. When i preview/viewport rendered it it looks fine. When i go to do my final render it doesnt look fine. Some places its missing the contact where i’ve animated and its like skipping key frames etc.
Ive noticed…
When i go backwards on the timeline it goes a bit off. Its more accurate if i scrub with the mouse as well then with the left and right arrow keys…
It’s real frustrating cos i’ve been counter animating just to get the render looking right and the only way to check it is to render! lol…man i really hope theres a simple solution.

well ive found out that the hooks from my spline ik curve vertices arent following precisely the control pose bones…
Like they do if i scrub with the mouse but not when i use the arrow keys and i guess not when i render

ok! i think ive got it…well not solved it…but the problem is some updating thing. Like if you use the arrow keys it screws up but if you change a value here or there on anything just about it! then it goes and updates the rig and therefore the animation. Any ideas why this is? and how to fix it?

ok i figured it out, heres the issue. Keep the bones for controling the spline seperate armature.

"When setting up the rigs, it is currently necessary to have the control bones (for controlling the curve) in a separate armature to those used for deforming the meshes (i.e. the deform rig containing the Spline IK chains). This is to avoid creating pseudo “Dependency Cycles”, since Blender’s Dependency Graph can only resolve the dependencies the control bones, curves, and Spline IK’ed bones on an object by object basis. "

well that ends that! nice talking to myself =P ive learnt my lesson too bad i cant quickly fix it.