Friedrich Karlsvalt

I am an SL sailor and pilot. I have noted an issue that is one of the most puzzling I have come across here. When I rez a vehicle, either boat or aircraft on a sim and move away, crossing a sim border; I can look back and still see the sim I had rezzed and departed. Once I am several sims away, and can no longer see the sim in which I rezzed, I can return to that sim, and find it missing. The entire sim that I rezzed in is missing. It appears on the world map and the mini map (Radar), but I cannot see it. If I try to enter the missing sim, I crash. Has anyone had this issue and how to I resolve it?

I have had an incident occur three times in 6 months. My skin will involuntarily change from my normal avi to the black rabbit skin located in the initial outfit folder in the inventory library. I have searched SL blogs but have not seen read or located anyone else having this problem. I use Firestorm 64 bit, but it had occurred in an earlier version of Firestorm as well. Cache is cleared routinely. Is this a SL glitch.