Fast Track Pro, Yosemite 10.10.5 NOT working with Avid driver

[brdeveloper]

Hi. This is my first post. I'm an amateur musician, so recording and mixing is one of my hobbies (other ones include photography and programming). I'm a long time Fast Track Pro user. From my memory, it was never a rock solid interface in terms of stability. Since Snow Leopard it went unexpectedly offline, and sometimes restarts were needed to bring the interface back to life. Well, at least it used to go back to life after a restart.

So now my Mac is on Yosemite. The OSX-bundled FT Pro driver works well, but it's fixed in a spartan configuration of 44100Hz/16bit. So I proceeded to the official driver installation, version 1.9.5. No success in the first install... the interface only gave me noise. I even tried to apply the firmware update contained in the dmg package, but it doesn't find the adapter. So I researched in forums about how to get rid of the Avid driver, since the uninstall app on the .dmg doesn't work (C'mon, Avid, where did you test that?).

Well, after a manual cleanup I tried re-installing Avid drivers. Now I had success, although the firmware update app can't connect to the FT Pro yet. Well, at least I finally got my FT Pro working. Did a test project at 48KHz/24bit in Reaper and everything went fine... until I restarted my Mac. FT Pro died again and a new reboot didn't solve the issue. Checked every combinations of restarting with the interface turned off, turned on, etc: no success. so I'm in the stage of getting rid of everything again and being back to the OSX's spartan driver.

In short, I ask the following question: is there a way to save this audio interface? Should I downgrade OSX to Mavericks? Mountain Lion? Should I relentlessly blame Avid in the hope of being listened? If I have to buy a Focusrite just for the sake of software compatibility, I will blame Avid even more. Come on, this interface never worked decently on Macs (considering I started using it on a Mac Mini with Snow Leopard). Perhaps on Leopard and Tiger it performed decently.