Never seen any of the bugs you describe. Plus, the Cool VL Viewer doesn't implement the v3 rendering engine, but v2.6's and the rendering engine got nothing to do either with what you describe... I suggest you start over by making *proper* bug reports (
see the rules for this forum) so that if there is actually a bug, I can get a chance to investigate it...
I would also suggest that you verify your network, since failed teleports and race conditions with attachments got nothing to do with the viewer itself, but instead with network issues between the viewer and the servers (be it an overloaded network on LL's side or bad network on your side).