I’ve seen several problems with the old soundmax drivers. Sofar I was able to solve all of them with newer drivers or a fresh installation of the os. I’m not saying you should do a fresh isntallation of the os! See if you can find newer drivers first! Sometimes even older drivers than the ones you have can solve the problem.

This site is good start to see if there are newer drivers for this particular card.
http://forms.analog.com/Form_Pages/soundMAX/soundMAXtechSupport.html

Another site worthwhile to check is www.driverguide.com