Sonar LE driver error and no sound

I have installed the copy of Cakewalk LE that came bundled with my new Edirol UA-101 USB interface.

While the Edirol interface works fine (sample audio plays on it, and the system can hear a microphone plugged into it), I am getting an error when I try to launch Cakewalk LE:

"The following drivers either do not support the current audio format or are in use by another application. Please choose whether you want to disable them or use them anyway:

Sigmatel Audio
1: EDIROL UA-101 1/2
1: EDIROL UA-101 3/4
1: EDIROL UA-101 5/6
1: EDIROL UA-101 7/8
1: EDIROL UA-101 9/10
1: EDIROL UA-101 11/12"

If I click "use them anyway" and load up any of the Cakewalk sample tracks, I then get the following error when I try to play the track:

"Unable to open audio playback device. Device may not support current project's audio format or may be in use."

I've tried resinstalling the software, but it's the same problem each time.

What is the problem, and how do I fix it?

Thank you in advance for any help.

The solution is here:

http://www.cakewalk.com/Support/kb/kb2003174.asp

Hello,
I had a trouble with "no MIDI outputs selected" problem (I also have SONAR LE but with Samson G-Track). I couldn't hear anything play although I could see it was recorded. So I decided to try to do something. I chose "options", then "audio" and highlited the driver for the output. The effect: I had an additional error, the same as you do ("The following drivers either do not support the current audio format or are in use by another application. Please choose whether you want to disable them or use them anyway"). I chose "use them anyway", chose "audio" then "options" once more and in "advanced" set driver mode to MME (32-bit). And the effect was just stunning: all my problems were resolved! - I have MIDI outputs and inputs selected, everything's correct with the drivers, and I can finally hear my music play.
Hope this helps!

SJ,
Yes, we would generally recommend you use the Edirol unit excluxively. This will ultimately give you vastly better performance.
However, there are some things that may trip you up as you get started. A biggie is the lack of soft synths included in many packages. Since you have an Edirol interface, there is a fair chance that your package includes the Edirol VSC synth. Click Insert>DXi Synth from the tool bar. If the Edirol VSC shows up in the menu, you can use it. Find tutorial #8 in the help files to get more information on how to use it.
If you do not see it, you may want to stick with the on-board sound card for the time being, 'til you get your feet wet.
The problem is that Sonar LE is packaged with many different variables, and we don't know what else you have to work with.
In Mikes case, he is using the built-in sound card, and using the Microsoft Wavetable synth that comes with the computer. The MME driver mode makes that available to use. This compromises overall performance, but does allow you to get something done.
For now, run with what is working for you. Get a feel for what it is you are working with. Read the Help files. Yes, I know it's boring, but there is a wealth of information there. Ultimately, you will want to bring the Edirol online, but it will be much more satisfying if you have an idea of what you are doing, and what to expect.
Also, check out the other forums here. There is much to learn, and many knowledgeable people here to help you along the way.
Once you get the first few weeks out of the way, it really starts to get fun.
Good luck, and welcome.