A similar thing happened to me awhile back in the CS 707.  I was climbing out of Perth, headed for Sydney all fat, dumb, and happy when the plane stalled at full throttle as I was passing through FL 31 to my cruising altitude at FL 33.

Figured at the time I must've brain farted something.  I don't read the manual or follow checklists as rigidly as I should......or maybe it was just dem darn pesky gremlins again.  Maybe helicopter pilots just aint smart enough to fly big fast jets.  Anyway, the situation hasn't repeated itself.....yet.