I've been working with this issue a little bit more, here's what I know. I've uninstalled and reinstalled the new driver multiple times. On restart, the computer is inoperable with my KB37 VU meters lighting up. I tried opening both the "Line6 Audio-Midi Devices" and "Sound" tabs under system preferences. While connected, the Line6 Audio-Midi Devices takes about 2 full minutes to open, only to report that there isn't anything connected. The computer completely freaks out when I hit Sound, and it reports that it can't open that preference pane. At this point I can't even shut my Mac Pro down without doing a hard shutdown and disconnecting my KB37. I've attempted everything at this point to no avail, so still no luck for us KB37 users as far as I can tell.