A few years ago I was doing a podcast and picked up a Fast Track Ultra to capture and monitor audio. I also use it for audio playback since it has a pretty nice DAC and a decent headphone amp. A problem I've run into though is that periodically my Mac will stop seeing the interface - it won't show up in audio options or in the device listings. If I try to power-cycle the Fast Track, the Mac locks up hard and I have to hold the power button to restart. After a restart, the interface comes back up. Usually it stops seeing the interface after the computer has been asleep, but it's not consistent - I put the computer to sleep before work each day and maybe one day a week when I get home the Fast Track is gone. Any time it happens I've resorted to just restarting the Mac since it's more graceful than a hard reboot. I've updated the drivers and tried different USB ports, going through hubs and not going through hubs, etc, with no success. The Mac in question is a Late 2013 MacBook Pro, but I've also had the issue on a 2004 Power Mac G5 and a 2007 MacBook Pro. Any ideas? Any recommendations for a new audio interface?