From Cakewalk 9 to Sonar 8 sounds bad

I just installed Sonar 8. I still don't know my way around much.
When I open a Cakewalk 9 .bun file it opens fine and looks good but it sounds almost like it is overdriven. Lots of crackles and pops.
Ofcourse, the tracks are not over driven and it happens on every track.
Desperate for help because I'm dead in the water as I sit now.
Thanks for any ideas.
Chuck

Thanks for the response.  Like I said, I just installed this, but I failed to mention it was on a new computer.  When I first opened Sonar and opened a bundle file it gave no message, BUT when I simply double click on a .bun to open it I get the message that my onboard output drivers are incompatible.  I guess this must be it.  I plan on buying some sort of USB audio interface soon, (my old system was built around an Aardvark Q10) and I hope that solves the issue.
I am assuming that a USB card/interface would "replace" the onboard sound just like the Q10 did on my old system. Does this sound right?

Thank you.