I've begun to experience problems with my tracks playing different instruments than what was recorded and saved. I use a MacBook Pro 2.5 GHz i5 w/8G RAM, and I'm using Spectrasonics Omnisphere, Alchemy, and Logic plug-ins all together on the majority of projects. I'm listening to the completed project for mixing purposes and suddenly the sounds have changed to some other instruments on multiple tracks at a time. Have never had this problem until recently. I work from a 2TB external solid state drive with a 3TB G-drive backup, so my internal drive still has over half its 499GB capacity. My sounds are store on the backup drive. I'm having to reinstall the sounds on the tracks recorded and it works with some exception (different sounds than originally selected although the track shows it's the right voice name). I've lost valuable tracks before I could figure out to just try and reload them, and it worked. But it keeps happening. Any answers to this problem please? Thanks.