CS:GO Playermodels in SFM - IK Rig wrecking model proportions

I’ve been wanted to hand-animate in SFM using the Counter Strike: Global Offensive models for quite some time now, but when the IK rig attaches it screws up the proportions of the model. The thigh bones move down and elongate (but the pelvis remains stationary) and the arms shrink ever so slightly. Does anybody know of a way of preventing this from happening?

Click on the thumbnails below to see the effect of applying the IK rig - no other changes are made to the model and this happens regardless of how the model is posed beforehand.

http://thumbnails115.imagebam.com/50156/af1d52501551773.jpg
http://thumbnails116.imagebam.com/50156/e248dd501551776.jpg
http://thumbnails116.imagebam.com/50156/0fcc57501551777.jpg
http://thumbnails116.imagebam.com/50156/80c68c501551780.jpg

Thanks very much in advance for your help!

The problem is IK rig script calculates IK using “idle” or “ragdoll” sequences from the model (probably only idle). They are broken and so does the applied rig. I have a normal sequence, but not the model. Recompile it yourself with the attached animation by replacing idle and ragdoll sequences.

http://rgho.st/82l7qDbgv

OFFTOP: How did you get such soft and uniform lightning in SFM? Why did you disable the shadows?

If that’s true then I’ll read up on (re)compiling models and give it a go - thanks for the tip!

P.S. The lights are actually disabled which is why everything is “equally illuminated” - working without lights makes the viewport run more smoothly, especially in a scenebuild with ~16 spotlights.