Hmm, that volume showing on your monitor could be the monitors own sound display showing on the digital interface most monitors now have. Try to find a button on the monitor which will close it off. One should.
As for the bvolume, it is possible the moniutor one could have been interferring but probably not.
Open the Volume Control, by right clicking the icon and going to Open Volume Controller.
Try changing it here in the master, and also drag the other ones up too
I hope this works and helps.
If all else fails, you can always try installing the sound drivers again!