Hello Sonet -
The tscvirun.prj should only 'popup' on a step of there is a breakpoint somewhere in the C code, or if you have instructed TestStand to 'step into' the step. Check through the tscvirun.prj for any breakpoints. If you don't see them, you may want to rebuild the tscvirun.prj with a fresh copy by investigating Configure>>Adapter>> CVI Standard Prototype Adapter settings. You should see a button that will let you reset the tscvirun.prj here.
-Regards
Elaine R.
National Instruments
http://www.ni.com/support