This is a spatial mode issue....TEM 01 or TEM 10. There are only two reasons this would happen...severe shock causing misalignment (unlikley as these are very well built) or someone hooked up the head to the wrong supply and ran it. Sam fixed an Ignis that had this happen to it. This could be repaired by Laser Quantum but that woudl cost real money. I will send you a PM with a low offer; I hate import hassles.Phil