Animal Crossing City Folk issue

[SeBz]

Hi guys

I'm having a slowdown problem when running near trees, not a fps drop. Its like a glitch where it "stutters" and it only happens every so often and only from running around trees. I have everything set to default on my Dolphin 4.0, apart from the Video backend is openGL and the internal resolution is set to 1.5 native. I've tried changing a lot of settings in order to fix this and its driving me insane lol

Computer Specs in Profile.

Thanks in advance