I installed version 0.9.6. The music player lag + mute issue is gone. Also, when you boot the phone, it doesn't lag at all.. It became completely smooth from the first minute you boot. No need to "use your phone for an hour or two". Damn, now the N9 looks 99% bug-free. This is awesome!

so again.. Take note: FasterN9 v0.9.6 works perfect for PR 1.3.