Aurora R9, blue screen after bios update 1.0.11 SOLVED

Tried everything I (and tech support) could think of.  The stopcode was "Driver Verifier DMA violation". Dell was sending a technician.  I put the machine up on the desk for service and noticed an old, unused firewire card still installed; completely forgot about it.  Pulled the card, booted fine first time.  This was embarrassing; glad I cancelled the service before a tech saw that.

Dell support was very good through this and I give them credit for sticking with me.

Hope this helps someone else (that's not as daft as me).