What causes this message: "warning: viewer defaulting to fastest ts" ? - simulink

Hi all! I have a really simple question.

Has anyone encountered the 'warning: viewer defaulting to fastest ts' message before?

This has been occurring in matlab 7.0.1 simulink. I have a really simple simulink mdl file example, which includes just one pseudorandom generator block and one scope (for viewing).

Everything appears to be running just fine, except I don't know the meaning or reason behind that 'warning: viewer defaulting to fastest ts' message. I assume 'ts' means time-scale.

I have attached my really simple pseudorandom generator mdl file (in zip format) to show. When I run this file, the matlab command window will pop up that 'warning' message. Anyone know what that warning relates to, or what I could do to address that warning? Thanks very much for any help in advance!