use of P1/P2/P3... always return compilation errors

[owneroxxor]

Why when I try to use those variables, they return compilation erros, at ALL cases?
http://prntscr.com/aqh2ww

BTW, the "P3" in the formula "P1-P3" in the yellow box is tricky. I set the formula to "P1-P2".Then I hit "Update". When I open that box again, the formula now is "P1-P3" something is going wrong here.

BTW: the compilation error occurs for ANY use "P" variables, P1,P2,P3,P4,P5,P6....

[fxDreema]

Interesting, I have to investigate this