OK! You can see what my interface is in my signature, and I need to figure out why everytime I open Sonar 8.5.3 I get an obnoxious POP when it engages the Alesis driver.  It didn't used to do this under the exact same conditions, so I'm wondering what I should go check, and/or change.

To prevent damage to speakers you should be in the habit of turning your monitors down or better yet, off when shutting down or starting up your computer, these pops can and will happen. I find it is random on my system and it only reminds me that I have forgotten to turn off my power amp again. But I'm in the habit of turning my monitor send control down low before I shut down so the pop is fairly quiet. I think it could be real bad if they were on full. 
As far as the drivers go, I have mine set for "Share with other programs" and once my computer is booted, I can kill Sonar, open wave lab, play in Win Amp, open a movie re- open Sonar etc, and there are no pops. The drivers are running already and are not initiated by Sonar. I only have my Tascam as an audio device, there are no drivers installed for internal sound. The POP coincides with the USB activity light on my interface lighting up which is during boot up.  
 
Do you get the pop if you turn the audio engine on and off? 
 

Good suggestion to turn on pwr amp AFTER I boot Sonar.  Yes, I DO have the drivers shared, and I don't think it pops when I turn on the engine, but I'm not positive.  Thanks for the tips.

The advice to turn the speakers on last and off first is solid advice.
 
We used to do that all the time with our PA.....  the amps were last on/first off for that very reason. Too easy to damage a speaker cone or a horn diaphragm. Studio monitors are no different so treat them with kindness.
 
My system here in the studio has a very low level sound that lets me know when the system is ready to process music. If it ever starts popping, I will certainly use the LO/FO procedure.