Scorching Ray CWC Icestorm still crashing server instances

Thought I'd mention that I am still getting the occasional server instance crash/lockup when using Scorching Ray, Cast While Channelling, Icestorm (Whispering Ice).

Game freezes, can't do anything except exit to Login Screen as nothing else works.

/oos has no effect, /bug has no effect. Latency just flatlines.

Latest lockup was in uber lab. Character RayGunner in Standard league.

No problems apparent whilst running WinMTR. It is NOT anything to do with my internet connection.