changing sample rate in USD set up

Everytime I attempt to change the sample rate in the USD Set Up for my mix plus system from 48048 to 48000, my computer (G4) crashes. Is there something I'm missing that's not allowing me to change this? Thanks for any help. This system is new to me.

Hi, Use of the USD Setup application when the USD is connected to a digiSerial port (on either the MIX core or MIX farm or d24 Audio cards) IS NOT supported and may result in a system freeze or crash. You can change the sample rate in Pro Tools or connect the USD to a local serial port on the Mac if one is available. If you can supply more information about the version or Pro Tools you are using and the rest of your hardware. Thanks, Digidesign Tech Support

Hello, Thank you for responding. I've tried it connected, and disconnected to the digi port, with the same result. I'm running pro tools 5.1.1cs5 (tdm system) and the USD is 5.0.2 Even when I have the sample rate in the session at 48000, it has followed the USD at 48048. These were older sessions that I've brought into the new system.

Hi, I am a little confused. Do you have Pull Up engaged in the Session Setup Window? Do you want the session at 48000 or pulled up to 48048. It sounds like you have a 48000 session with Pull Up engaged and just need to toggle it off. Please give me some more details or let me know if I am in the ballpark. Thanks, Didigesign Tech Support