There's no need for asio4all if you audio interfaces already have proper asio drivers. And as I said you can use 2 devices if you swicth to WDM mode , this is really what asio4all is doing anyway. ,
Asio4all can cause many issues once installed and it's not that simple to 100% remove it. 
 

Your always best using the Devices ASIO rather then ASIO4ALL...

And if you must use ASIO4ALL make sure it is configured properly,
as has been stated.

Our Band uses a Mackie ProFX22 USB 4 Channel Mixer...works fine...

Guys - Behringer has started providing ASIO4ALL instead of proper drivers ...

Thanks for the help, everyone.
 
I tried the suggestion of changing the driver mode, and that did indeed cause Sonar to see the USB I/O. The USB connection caused a persistent whine, however, which is something I noticed when messing with it in the Windows Control Panel as well. I don't know what that's about. Thanks also for the info about ASIO, I don't know anything about these driver modes. I switched to WDM based on recommendations here.
 
So playing back an existing project using USB out, lots of stuttering (and that persistent whine). Also in a recording test, there were lots of pops and dropouts (which were reflected in the waveform, so they were during input). I unplugged the USB cable, the whine disappeared. I switched my I/O to the regular M-Audio (which is in fact Delta Audiophile), and left the mode on WDM. All seems to be happy now. Plus, my input drivers now list as "Delta AP 1/2) and "Delta AP Monitor" etc, where it used to be something else longer. My foggy guess is that switching to WDM is making the card use different drivers which have different names, yeah?
 
While I'm learning here, what's the difference between the 1/2, monitor, multi 1/2, 3/4, 5/6 and SPDIF? As mentioned, my card only has a single RCA stereo in and a single stereo out, so I don't understand why there would be 3/4 and 5/6. Maybe those just come because the drivers have them, but my actual card doesn't support them? So then what's Monitor and SPDIF?

in ASIO 
 
LEFT INPUT 1/2
RIGHT INPUT 1/2
STEREO INPUT 1/2
 
that's the nomenclature it uses.
 
again, tho, as I said above; the delta and the berhinger will have TWO DIFFERENT CLOCKS.  if you try to use them in the same project, regardless of using WDM driver mode or not, you WILL have timing drift between the tracks.

Sorry to be obtuse, but what do you mean by "use"? I am using the behringer as my mixer, and its effect send is going into the sound card. the sound card's out is going to the tape in on the behringer, for monitor purposes. I am not using the USB at all now.

You should still use ASIO mode whenever it is available. I only mentioned WDM mode if you were going to try and use both interfaces to record. ASIO only allows one device. WDM mode is more forgiving but does come with pitfalls. 
In loopback testing I found WDM mode was out of sync. So I don't recommend it for overdubing at all. It will work fine for the live recording because syncing tracks is not involved unless you are using 2 devices. 
  
As that's a good point about the 2 devices possibly not syncing. I have yet to use my Yamaha for a full recording in tandem with my us1641.  I just set them both up and tested a short piece in Sonar to see if it would work. Both the Tascams  inputs and the Yamaha ( marked as Steinberg ) show on the inputs list in Sonar. I'm foggy but I do seem to remember the Tascams SPDIF do not show in WDM mode.... 
 
I leave everything in ASIO mode and it seems to not cause any issues with Sonar running and the Yamaha playing back music from Windows. Note I am staying in 44.1/ 16 which might make a difference. 
 
I have recorded straight stereo from the Yamaha mixer to Wave Lab and Sound Forge and that is fine too. I get no hums or issues. But somehow it doesn't suprise me that a Berhinger would hum. It really sucks that they are not taking the trouble to supply drivers. The USB connection is therefore pointless. Take it back and buy a Yamaha, Mackie or A&H. 

I didn't buy the behringer for the USB functionality precisely, just needed a new mixer and since it had USB I thought I'd try it. I paid $80 for it. Is there a reason to go with another mixer besides behringer if the USB is not an issue? When you say "pitfalls" using WDM, what are those exactly? 
 
Keep in mind, I'm a "prosumer" who takes his work seriously, and has real releases on a real record label, but I doubt I'll need to provide music for games or films or anyone paying me big bucks for it (at least not if I can help it).

jkoseattle
Sorry to be obtuse, but what do you mean by "use"? I am using the behringer as my mixer, and its effect send is going into the sound card. the sound card's out is going to the tape in on the behringer, for monitor purposes. I am not using the USB at all now.

If you are not using the USB part of the mixer then it won't be a problem.  the clock timing issues will occur only when you're trying to use two soundcards.  the USB device for the mixer and the delta both are soundcards.

kitekrazy1
 
Take it back and get the 802 without USB.

+1
Since you already have an interface then yeah, you don't need a USB mixer.  A standard analog mixer with the usual I/O will do the job just fine.