The new X3 pole sections are different ID and OD to all of our other poles - although they look very similar.
Because of this we cannot guarantee that they are compatible and in fact when mixing and matching new sections most of the smaller sections on the X3 will not fit new sections on the Series-II Xtreme poles.
However just to confuse the issue slightly, some of the X3 sections will fit older worn Series-II Xtreme sections - this is because older sections will have worn somewhat and now have a larger ID than when new - this allows the slightly larger OD of the newer X3 sections to slide in. James this is why your new X3 section #1 fitted your Series-II section as it must have been somewhat worn - another client may try this and find it too tight a fit.
I hope that this has helped clarify the situation. I would have liked full compatibility between the sections, but this was not possible to do and also bring in the X3 with its greatly improved strength and rigidity.
We will be continuing to manufacture Xtreme Series-II sections for some time to come for those wanting replacements and spares.