I am trying to save poses for an artillery gun which are basically the firing and towing positions but although the poses are added to the pose library, when I try to apply either they don't take. I am adding them through the add button in the library and have used every option but they just don't take. Is it me or is it P7? Any help would be appreciated. The gun is a figure not a prop.

Do the PZ2 files look proper?  Open brackets matched by closing brackets?

Does the figure have any duplicate names, like a frame named "body"?

If all else fails, try removing all the "staticValue" lines from the PZ2.  
In P7, I've seen a pose that fails to hold because the "staticValue"
lines were causing the figure to return to its default.

hmm..might try it manually. From what little I know, the carriage, trunion and barrell would move on only 1 axis, at least when it's stationary. The real thing uses dials (or some did..;)

No Duplicate names or staticValue line. However there was a refFigureJamesG2 lines with a figure and associated body parts and a thighlength=0 reference which I removed. The two poses are towing position (legs together) and firing position (legs splayed). the firing pose took but the other didn't and looking at both pose files the key values were exactly the same. Changing the key value in the tow file allowed both poses to take but when you try to move an individual leg and then apply the pose again they kick everything out of kilter . Sorry if I'm not explaining everythin clearly but its easier to see whats happenning than explain it.

Hmm....   Sounds sort of like an Inverse Kinematics problem.  
I don't know if the gun was built with IK chains; it probably 
shouldn't have been built that way.  If it does have IK, you 
should certainly turn off IK for all the legs before doing any posing.

No IK chains in the figure, just one dial to move each leg in and out and one two move the leg lock. Considering the trouble it's causing, I'm wondering whether its worth using a pose at all.

That's truly a puzzle.  Could you show some screenshots, including the hierarchy window?  

Might help to get better answers........

OK will put together a little slideshow....

I'm beginning to think its an ERC problem as I've noticed something else happening outside of the pose issue that shouldn't be. I'll get that sorted and report back.

failing that..a nice pile of sandbags can hide a multitude of model failings...;) Not a great idea, but  a potentially useful one.

Or PhilC's exploder maybe....

Not sure what would happen but try saving it as a prop with the pose you want and see if that works.

Well it looks as though it was something to do with the ERC after all. Decided to rig the figure again from scratch and voila, everything worked as expected, including any applied poses without modification to the file. So everything is again right with the world. For the moment anyway.....