I just realized that my AU binaries hide each other, meaning that when I have multiple of my plugins installed, only one of them shows to the host. I suspect there is some kind of identifier clashing, but I can not figure out wich one. Another possibility might be that i'm linking to the same library (would not make much sense thought). I'm using XCode 5 and building universal binaries. It happens in debug and release mode.
Any ideas? Do you need more information?