An optional viewer update has been released to resolve bugs found in 1.8.4.6.
The original release notes say that HUD objects are not shown in snapshots. This is no longer true. When HUDs were introduced, many residents wanted the HUD to show in snapshots without having to turn on the UI.
When investigating the fix to the nametags and text showing in screenshots, we found that the HUD could be displayed in snapshots without having the UI turned on. We have enabled this feature for now. If you don't want your HUD to show in a screen shot, simply detach it for the duration of the capture.
Release Notes for Second Life 1.8.4(7) Mar 1, 2006
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* Shiny objects are once again selectable from all angles
* Toruses with animated textures no longer affect FPS
* Snapshots can once again be taken without showing text or nametags