The newest version required me to change the sample rate on my sound card to 44.1 from 48.
so that means that every project that was recorded at the other sample rate must be converted to the new sample rate or it will not play and you will have sound card problems. Changing the sample rate of your projects that where recorded at another sample rate is very cumbersome. You might need to solve your issue with the other program that makes you use the new sample rate. Any program worth its salt, can run at 48KhZ 44.1 and 96kHz.
Samples rates cannot be changed on a whim.
About your wave files being busy, just delete your Pic Cache.
Cj