For some reason, when i have Sonar open, I can't play audio from any other windows programs.  If I try I either get an error.  Also, sometimes even if I have closed Sonar and then try to play a windows program, if will play the windows program every slowly and deep.  I can fix it by rebooting.
 
Any advice is much appreciated.
 
 
 

Preferences > Audio > Share drivers with other programs Tick

Make sure the other programs are also set to the sample rate.

Go to EDIT>Preferences>Audio>Playback and Recording and check the box marked Share Drivers With Other Programs 

haha beat me to it wookiee!
 

Only by a nanosecond Joden

As long as it is not ASIO...

sorry SimpleM, not true. Works even if using ASIO drivers as well :) 

I can second that I only use ASIO drivers and other things use the soundcard when SONAR is open

Also right click the audio device in Windows Sound card settings and check "properties->advanced tab" uncheck both "exclusive mode" options there as well. Windows can also lock out drivers by who grabbed them first.