When saving a pz2 the data for an IK chain will only be included if the IK for that chain was "on" when the pz2 was saved. When applying a pose that has IK chain data (ikchannels), the data for the IK chain will only be applied if that IK chain is already "on" in the figure, or if the pz2 is edited to turn the IK channel on. The relevant code to turn IK on in a pz3 is, for Posette:

figure 
        {
        inkyChain     rightArm  
                {
                on
                }
        inkyChain     leftArm  
                {
                on
                }
        inkyChain     rightLeg 
                {
                on
                }
        inkyChain     leftLeg 
                {
                on
                }
        }

For Victoria 2 Use "RightLeg" (upper case "R") etc. This code should probably go in the last figure block, it does not seem to matter that the code to turn IK on comes after the channel data.