yes there is a way to adjust the volume for the xm player using jaws;

the volume within the xm player doesn't work at all; (at least from my experience, the buttons there do absolutely nothing, just decoration);

go into startmenu, do search for volume, select adjust system volume;
then a box will come up with lots of controls;
it will have things like system sounds, jaws, internet explorer, etc;
these are volume controls for each program that is open;
select the volume control for internet explorer and this will adjust the volume of your player;