Major slowdown/visual glitches when screen fades

[Padoverc]

When a game has the screen fade to black, or get darker to signify the passage of time, the emulator either slows down to under 50% the usual speed, or has the whole screen get covered in what looks like diagonal scribbles, until the fading has ended. This is on 1.2.2 on android 4.2.2. Experienced in both Princess Crown, Trails in the Sky, Grand Knights History, etc. Just curious if there is a fix. Using default settings, auto frameskip, frameskip:1.