well I’ve already fixed this but to let anyone know who might also have this problem…
maya 2009 64bit linux
nParticles with shape names different than their transform names
like “inst_debris_nParticle” shape name of “idps”
that won’t cache, well it will cache but it won’t play back anything. Change the names back to nParticle1 and nParticleShape1 and your fine.
maybe no one else will have this problem. I started doing that from an old weta guy’s tutorial from like 2005 to speed up script writing. Seems like maya no likey now. Anywho, might help save someone some frustration.