OpenGL Renderer specular effects/ambient occlusion issue

[antoniodesousa]

I'm not sure is related to the specular effects, but the issue is very obvious in games that uses some sort of ambient occlusion effect or specular effects like the thunder power up in Mario Kart DS. When it hits you, it leaves some sort of transparent after effect with the silhouette of the thunder hitting your character. Here is a screenshot of the issue in the game Sideswiped:

This issue can be "fixed" if you quickly swap the screens every time it happens (very annoying though).
I tested the standalone version of melonDS and the issue is not present there.