Lose of external speakers volume and balance controls

Does anyone know what would have made my computer system sound control (volume & balance), on my external desktop stereo speakers Yamaha YST-M8 to quit functioning? I have volume to both speakers OK but no control from the front panel of the speakers any longer. Accordinging to my computer management the desktop stereo speakers are installed and functioning properly, but I have no control over volume and balance from them like I used too. The only thing I did was shutdown my computer, disconnect everything and moved the computer from one address to another and then set it all back up. I was very gentle and careful in handling the computer and components during the move. I removed the Creative Labs Soundblaster Live card from it's socket and re-installed it without any help. The Sounds and Audio devices control module is there in my control panel and all is funcitioning correctly so my computer says. I can control sound and audio devices from that console and select put volume control in the task bar area and control the volume there as well, but no external sound control on my speakers, which used to work fine before my move. Please write to [email protected] if you know a fix for this problem. Win XP w/SP1a is the OS. Thanks, Les