metering with surroundscope?

[tomcat]

Arrgh! more toys=more confusion.

pt 5.1 generator x putting out 1k it calls -18

Channel strip sees it as -20

Dolby surround tools, monitoring 4-2-4 sees it as -22

Surroundscope on the Center/Surround aux of dolby tools sees it as -26.

What gives? what can i possibly do to make my rig relate to the rest of the world, short of spending tons of lunch money on a dorrough?