The problem is that rotations aren't stored! - well not effectively as far as I know, there's some weirdness when checking the limbs direction.
Anyway, when you load in a bone animated model, all the limb rotations are at 0,0,0 - the animation is 'invisible', even if your looping a walking animation, you'd check the limb angles and get 0,0,0 all the time. But, if you rotate the limb, then that rotation is included, so if you rotate a hip by 0,90,0 - it'll probably be pointing to the left instead of straight ahead, and then the walk animation would be really messed up. That's why I'm suggesting that anyone rotating limbs with code should leave them un-animated, because working with an animation and rotation is a much bigger problem than working with just limb rotation.
For example, in an old game I made Operation:Invasion Evasion, I had a soldier model with full walking animations, but anything above the waist was left alone. Then, I made a little limbs poser program and posed the torso (back, shoulders, elbows, hands) to suit whatever gun they might want to carry. So the walking animations all work alongside the posed torso, meaning I didn't have to animate lots of different soldier models for different weapons, the soldiers could swap weapons. This also meant that I could turn and tilt the waist and back limbs to aim up and down, left and right, independent of the lower body and walking animation. To avoid eular hell, I prefer to limit rotations on a single limb to 1 axis, or at least only allow slight movement on secondary axis. Like, the knee might only rotate on the X axis - by limiting rotations this way it's easier to constrain them. I mean - you could work out what angle the knee would have to be at with simple trig, it greases the wheels for IK calculations if you like.
I think it's worth just loading up a bone animated model, and messing around with it's limb rotation, this stuff is very very handy to know, and not just for character animation. I mean a skeleton can be applied to any mesh, like a flag that waves in the wind dynamically and doesn't cost the earth in terms of performance, doesn't need a physics plugin - just a simple bone structure on a mesh and a coder who likes to experiment with this stuff
Heck, I've even used bones to lay a big patch of foliage over a terrain... used it to make a fully working hourglass (with sand trickling down), glass containers of liquid. And I use the limb positions for line intersect collision detection. Skeletons are very very useful things in DBPro.
I am the one who knocks...
