You have to make a new release of your product, you need to convince people you have changed it, but actually changing things is going to make them unusable. The solution? If you are developing a computer operating system for a captive audience? You need to add more eye-candy to keep the hardware manufacturers and retailers happy, then spend 18 months tweaking the sound themes.
Is it really true they spent 18 months to develop the windows start-up sound?