From 1PM SLT (US Pacific) until 4:30PM Linden Lab is going to try to stabilize the subsystem performance during the Sunday peak load on Second Life systems by selectively disabling services for the three and a half hour window.
Avatar profiles won't be available, group member lists and group information will be suppressed, no group proposals (and we presume notices) will be able to be created, and parcel traffic will read as zero. When 4:30PM comes around and these are re-enabled, you will need to either relog or clear your viewer's group cache to properly restore your use of the services.
This is supposed to alleviate load-related problems until additional, more permanent fixes can be rolled out.
