Well that mahogany, despite being very high quality, had always had issues with movement, very weird, since mahogany is one of the most stable woods available ( and yes it is mahogany ) that's how i started laminating necks, to avoid this problem, so i used that mahogany, laminated it and problem solved. The neck is still stable and straight as an arrow.
So i used the last piece i had, it had moved a bit but well, it had sit for 4 years so i thought that was normal, I surfaced both sides, planed it, sliced down the middle and glued another piece ( from another blank a bit older than that piece) and glued the whole thing together. I used regular titebond for this blank, the wood joint looks very good, no glue lines and almost invisible wood joints, i planed the fretboard surface and the oppossite to it, but left the sides untouched, well, about 4 months later, the neck blank has moved to one side, it's not much, but you can clearly see it, same as with the purpleheart neck blank.
So i guess the wood wanted to move anyways, but hell, it's dry, straight grained, laminated, and it's the last piece i have ( mahogany can't be found here anymore )
What i'll try to do is, finish the neck blank, plane both side and see if it moves again, if it does....then i guess i should toss it to the bin...
With the purpleheart blank i used high quality wood glue, not titebond since it can't be found here, but i've never had a problem with it, it's PVA glue, and it smells the same as titebond, except it is white.
The new neck i'll build, i'll use 2 ton epoxy, slow curing, made by Devcon...