This issue has been closed as 'Won't Fix' due to an extended period of time without updates. If this issue is important to you please let us know by posting on the AnswerHub or UDN, and Epic will re-open the ticket for further review.
GPU Particles will not rotate based on a negative input from a uniform distribution via Initial Rotation Rate
1. Add the attached P_RotRateTest.uasset to your content folder for QA Game
2. Open the QAGame Editor
3. Place the P_RotRateTest into the level
RESULTS: GPU Particle only rotates Clockwise or stands still, CPU Particles will rotate in both directions
EXPECTED: GPU Particles should have the same rotation behavior as CPU systems.
Head over to the existingAnswerHub thread and let us know what's up.