A some questions for you:

1. What sim is this happening in (32bit FSX/FSX-SE/P3Dv3, or 64bit P3Dv4/P3Dv5)?

2. What is your screen resolution and frame rate settings?

3. Have you set the display refresh rate to MAX using the 757 ACE?

I tested in all the sims with the display refresh rate set to MAX and MEDIUM and never saw any flickering on the edge of those displays. My screen resolution is 2560x1440, with the frame rate in the flight sims set to unlimited (all of them).
My computer specs are shown in my signature.