I'm using this in a buff I've set up, and it's being properly applied, because the mouseover detail window lists an increase/decrease to my resource output for that planet, but when I look at the detailed listings for my resource production for my empire, the resources output at that planet aren't affected.  I sat there and watched my credits increment for a while, and they were increasing at the full rate that was default.  Am I missing something here, or does this modifier not actually do anything?

Thanks for any help you've got.