It seems that counter list sends the keypressed signals to your program instead to ipdf.
About the keypress signals, Counterlist catch that signals and re-send to the open programs. It only re-send the left side buttons signals (pageBar, arrow up, arrow down, dot, exit and previus).
If you have added your program in the register.xml, to cath this signals the program should have gtk wmclass and title equal to the value of xResourceName of the register. If you lauch your program form a shell script, you should put "sh"
see this thread about buttons pressed: