SoundMax laptop driver incompatible with Sonar?

Not surprising; most onboard laptop soundcards are crap. Have you tried ASIO4ALL?

I was having a similar problem with setting up my SigmaTel audio driver in my laptop this weekend. Ended up having to go with the MME setting and running Wave Profiler. Even after changing that, however, I still had no sound at first. Then I went into my Audio settings and make sure my audio timing was set to my soundcard instead of none. (I think it's called audio timing ... when you open the Audio settings window, its the topmost dropdown box.) Then I closed SONAR, reopened and voila. Hope that helps.

What I don't understand is my laptop's soundcard has WDM drivers, but when I set SONAR to WDM and run Waveprofiler, it runs down all the Hz {?} settings and only 48,000 Hz{?} shows up as available. But when I try and open a project, I get that message you mentioned, saying driver not compatible or in use by another program, and I am unable to use SONAR in WDM mode. Bummer.

I think the only other options are to purchase a quality external sound card (USB) or one that goes in the cardbus slot. I haven't experimented enough to determine the latency on my current setup, but it probably is bad like yours.

A better tweaking utility is CodeStuff Starter; it does everything msconfig does and more.
Tweaking didn't help my Realtek drivers, though. Adding a pro- or pro-sumer audio interface is best.

I unloaded the tray, ran MS config, unloaded all the sound card related stuff, and rebooted. Same result. Sonar runs in MME mode only. That's it, I'm off to buy a sound card. Thanks for all your help!