If i do not change window's audio settings and let the 16x08 be the default, sonar works everytime. BUT no other programs have audio. Sonar does not crash unless i have changed the window's default settings.
 
I got spoiled using a PCI based interface with an excellent internal mixer that provided for all programs and sending signals to any others.
 
So, to use the 16x08 means using only one program at a time. Not fun. Cannot record from browers, cannot run CD Architect, and other such programs, while sonar is open. 
 
Oh well.

FLZapped
Have you tried replacing your standard ASIO driver with ASIO4all??

Do not do this - this is a band aid for hardware which does not have ASIO drivers.  Tascam has ASIO drivers, it does not need ASIO4ALL.  In fact, it may cause more issues just being installed (not active.)

jm24
If i do not change window's audio settings and let the 16x08 be the default, sonar works everytime. BUT no other programs have audio. Sonar does not crash unless i have changed the window's default settings.
 
I got spoiled using a PCI based interface with an excellent internal mixer that provided for all programs and sending signals to any others.
 
So, to use the 16x08 means using only one program at a time. Not fun. Cannot record from browers, cannot run CD Architect, and other such programs, while sonar is open. 
 
Oh well.

Do you mean no other programs work when Sonar is running, or no other programs work at all?
 
Again with ASIO drivers, you can only have one piece of software controlling the driver at a time.  If Sonar is running this should be sonar.  If it is not running, you should be able to have iTunes or a web browser using the driver and playing through the tascam.

BobF
I believe there are problems in the drivers for sure.  In my specific case, several DAWs (SONAR, Reaper, S1-3, Tracktion, MC8) all have the same problem.  The symptom is latency when switching presets in certain VIs and FX.  This include Sample Tank, AmpliTube, Waves GTR and others.  I can clear it up by going into prefs and selecting a different interface, then reselecting the 16x08.  Everything works great until I select another preset/model. in the plugs.
 
This does NOT happen using other interfaces, including Zoom R24, UMC404HD, GT-001, FA06 - none of which have this problem.
 
I'll soon be getting a new DAW.  If the problem with the 16x08 persists then it will either get thrown in the weeds or be relegated to stand-alone preamp and software-controlled mixer duty.  I was planning a new DAW anyway ...
 
I otherwise love the 16x08.  It's too bad it's sucking away my will to live
 
I still think there is a hardware problem if it interferes with your machine's ability to boot.

Update:
 
Preliminary, but much joy.  The 16x08 is performing flawlessly where it flawed before - even in a USB3 port.
 
I picked up a Dell XPS 8900; i7-6700, 16G, Intel Z170 chipset ... Intel USB ... I loaded just enough stuff to test.
 
The old machine has ASMedia for USB3.  That might've been the problem, maybe not.   Off to finish the days long transfer/reload process.  Once I'm done recovering drives and such from the old ASUS ('13) I'm gonna give it to somebody I don't like 
 
Another diff is the new machine is W10Pro, the old is 8.1

Non intel USB 3 is know to be problematic.  Hope its a permanent fix.

dwardzala
Non intel USB 3 is know to be problematic.  Hope its a permanent fix.

Kind of odd that my USB 3 drives take some connect and reconnect to show up on my Intel USB 3 and no issues on my AMD 970 system.  Maybe USB 3 is not perfected yet.

kitekrazy1

dwardzala
Non intel USB 3 is know to be problematic.  Hope its a permanent fix.

Kind of odd that my USB 3 drives take some connect and reconnect to show up on my Intel USB 3 and no issues on my AMD 970 system.  Maybe USB 3 is not perfected yet.

Yeah, my old machine (Intel CPU) with the ASMedia USB3 worked great with a wide variety of interfaces and devices.  The US-16x08 is the ONLY device that gave me grief.
 
FWIW, I've noticed that the old ugliness rears it's head if I make any changes to the system audio.  The difference now is that once it gets "reset", it stays good.
 
Given this whole experience, I'm convinced that the 16x08 drivers still need some love.  Maybe another driver update or two will get them 100% solid.  For now I'm able to work glitch free, which is a huge step forward.