Be sure that you are NOT using your 11R as the system audio. In other words that you are not playing music from the computer through your 11R or that no audio from like movies etc. and that none of the window systems sounds are coming through 11R.
Go to your devices and be sure that your INTERNAL sound card NOT 11R is set as default.
Be sure you have the latest 11R driver installed.
MANY, MANY people have had this issue, including me on my Windows machine.
Once you have set or reset your windows default audio go into the 11R driver control panel and see if you can change the sample rate. You should be able to now, and then when you open up those older files 11R will auto magically conform to the sample rate of the project.