(12-11-2012, 03:20 AM)luke76bg Wrote: I have read that old revision don't have this problem, so i'm trying to find out what kind of revision is needed.
This has been known to happen in Dolphin as far back as r6269. Going back that far, you'll be using unsupported Dolphin builds. They might solve this slowdown, but you might bring along other problems that have since been solved; there's no guarantee that you'll even get a better overall experience. Nothing's stopping you from trying though. I couldn't find anything about a specific revision that didn't have the slowdown.
About the slowdown, does the game drop down to a specific framerate, e.g. from 60 to 30? What does the game speed (represented as a percentage) look like during the slowdown. If it's something like 100% when the FPS drops, the game was probably designed to drop its framerate at that point. A lot of games do that to better use the Wii's resources. Haven't dumped this game yet myself, so I can't confirm if this is they case with Epic Yarn or not.