Hi maxoid
I noticed this issue in our grid as well already. Looks like since OpenSim 0.8 results for people search is build in as well now. As far as I could understand, this feature should be able to disable by empty the value for "Cap_AvatarPickerSearch" in the OpenSim.ini but this obviously does not work proper (yet).
I will try to make a new search module for 0.8 with the possibility to disable certain searches via ini settings, so the viewer does not get double results and I will let u know here as soon as it is ready for downloading
Greetz
FoTo50