Super Monkey Ball 2 Netplay causes my game to flicker very fast.

[Tolemi959]

Whenever I start SMB2 using netplay it causes my game to flicker real fast (even with VSync enabled) and makes it 100% unplayable. This occurs even when I am the only one in the Netplay lobby whilst launching the game. This doesn't happen for my friend. I use basically all default settings (as far as I'm aware). What gives?

I've tried both the 5.0 release and 5.0-148 version.
AMD Radeon HD 7800, 8GB ram, Windows 10

[Super David]

Have you tried playing the game online with dual core turned off?