Hi there, I'm installing Sonar LE on my Windows 7 32 bit laptop and trying to set up my MOTU Microbook II as the Audio Device. I'm in Preferences, Devices, and the Microbook II shows up, but I cannot select the Check Boxes for the MOTU Inputs/Outputs. The only thing Checkable is the "ASIO4ALL v2".  What am I doing wrong?

The MOTU should have its own ASIO driver. Many have found that asio4all is very problematic. We recommend uninstalling it as a first step to getting things working properly. Then use the proper ASIO driver that came with your interface, checking on the MOTU site that it's the latest version.

Page 37 of the user guide shows how to select ASIO as the driver model within Sonar.

Thanks! Uninstalling "ASIO4ALL v2" let me choose my MOTU Microbook as the device.

Now I have another stupid noobie question: I drag a .WAV file into a new song. I have the Master Output set to my headphones and click play.  It plays and I hear it. Then I click Stop, which it does. But when I hit Play again, I get a dialog window that says: "Unable to open playback device.  Device may not support the current project's audio format or may be in use." Since I just played it, I know it's supported, so some how it must be in use...
 
I've been through the Hardware Setup Guide quite a few times, but still no luck...
 
Please, what I am doing wrong? Thanks.