I've noticed that every time a pose is loaded from the "pose library", part of that loading procedure is to turn off IK on the target figure, apply the pose, then turn it back on.

   I don't believe that this on/off of the IK should be done, and this seems like a bug or an oversight.

   This does two things:
1) If the document is long and complex (lots of keyframes), applying the pose takes a long time (due to the IK calculations on all keyframes)

2) All of the previous keyframes on the figure have a chance of "breaking":, depending on the extremities of the pose. This is because turning IK on/off on a posed figure has some error, which can be quite significant depending on the pose and figure.


   I tried playing with the way the poses are created, and playing with manually editing the pose file to see if I could trick poser into not doing this.

   Does anyone else see this?  It can be pretty easily tested by creating a document with something like 5000 frames, Keyframe nearly all of them (like, 4900), then load a pose near the end. Do this both with IK on and off on the figure, and one can notice a significant difference in the time to load the pose.

   I don't care so much about the load time, however, the unwanted pose changes to previous frames means that the pose library cannot be used at all (for figures/documents where IK on/off changes the pose significantly).

I never turn IK back on if I initially turn it off upon loading a figure.  Some figures will load without IK depending on the model or whether the CR2 was modified to turn off IK automatically.  I don't do animations, so someone with experience could elaborate further on the advantages of using IK in animations.

As a quick note on this, I created a completely blank pose CR2 file  (  just  { }  ) and this behavior still occurs.

So, it seems that the IK  on/off  is a "hard coded" behavior of how Poser applies poses. Perhaps there's a reason for this, but this seems very non-ideal, heh.

Sorry for bumping my own repeatedly..
I discovered a workaround is to move the created PZ2  (not CR2, typo above) pose file to the "Expression" library as an FC2 file, delete the XMP file, and hand edit slightly, and now it works to actually apply a full pose with IK on, quickly and without problems.

The hand edit is removing the second top-level document partition, just combining them and letting the I target actors be defined twice..The 2nd version of the IK targets have the correct position parameters, so they're applied properly.

Which version of poser are you using? Because with the more recent versions, you don't have to turn off the IK to apply a pose. Of course, I'm assuming you're loading a pose not building one of your own.

This is version 12. It might be fixed in 13, but I can't check.

I have, indeed, created my own poses, but I've noticed the behavior described for all pose files, created by me or not.

It isn't that the pose won't apply (it does), the behavior is that applying a pose to a figure with IK on, which has many keyframes in the document, can take a long time, and can actually alter the already-created keyframes for that figure in the document.

As mentioned, I can use a completely blank pose file ( just open and close braces) and this behavior manifests. It seems like turning off IK on the target figure (if it's on) is a first step performed by Poser when applying a pz2 file in general. The observation that I can re-name the file to FC2 (an expression), and have poses apply with no problems seems to bear this out.
  That renamed FC2 file does require the edit as above, but that just seems to be because some library types will only read one top-level object whereas pose/character files will accept more than one.

Another way to see this problem:
   It seems that various conditions will cause IK application to calculate with greater error. One thing that causes this to a high degree is non-uniform scale of one of the IK segments, along the the "length" axis. For instance, load any poser figure, change the "yScale" of the thigh and shin to soemthing like 70%,  fix the foot position to be in reasonable range of the IK motion, then turn IK off and on a few times and watch what it does.
   Since pose application does this " IK off/on " each time, all existing keyframes of the pose get more and more messed up as every pose is applied form the library.