That does seem odd.
Can you clarify if this is something you saw change after installing SP3, or has always been blank in your console?
if you haven't already done this, why don't you try to create a filter to maybe select a node list...watch for the results...then change it back to being empty and SUBMIT it and watch the results again.
sometimes, just adding a FILTER and turning around and then deleting it will clear up this type of thing. undocumented type of stuff you know... good luck.
Wow, that just fixed my same type of issue after upgrading to NPM SP5...