Keystone Mask flashing

[dirtyjohn_lv]

R5, the keystone mask effect keeps flashing in and out of the mask when previewing. When you send it to a layer it stops.

Tried this on a Sager NP8678 with a 980m 8GB, driver 354.35, Win10x64(Sager doesn't provide any newer driver yet)
On my main server with the Titan X with driver 358.50 Win7x64 this doesn't happen.

https://drive.google.com/file/d/0B7mXx- ... sp=sharing