I know this was reported ages ago, but I currently have no issues using YEP_CoreEngine with MightyMouse v1.7.1. I've actually never had issue using YEP_CoreEngine & Mighty Mouse together. As long as you put YEP_CoreEngine higher on the plugin list than Mighty Mouse, then nothing in my plugin she be getting overwritten or anything like that. You may have another plugin that's actually to blame.
