enabling fragment program causes invalid_operation

Hello,

I do some very simple drawing (the smt tutorial demo program from pauls projects), everything works fine. But when I try to use a very simlpe fragment program for rendering, nothing is drawn anymore and every rendering call causes “invalid operation” (glGetError()). I enable NV_Fragment_Program with

glEnable(GL_FRAGMENT_PROGRAM_NV);

and bind the program with

glBindProgramNV(GL_FRAGMENT_PROGRAM_NV, id);

and after the DrawScene() call, NV_FP is disabled. In the project I am working on, this works fine and the fragment program is used for rendering. in the pp demo app, I only get invalid operaion (as described above). I don’t understand that. The smt demo program is extremely simple, I have no idea why rendering with NV_FP doesn’t work. Any idea?

Thansk and Regards,
Jan