I am actually having the EXACT SAME ISSUE and I was told the same thing by the person who invited me here. I am coming from IMVU as well, i know that my computer isn't having issues because it's only sl that's doing this to me.. I find that to be very odd... I was also having this weird farting thing going on with my avatar until I left the room and reloaded.. Then started the screen thing that you mentioned.. Along with the screen thing, I kept getting a message saying that my computer was blocking the graphics... I have no idea what this means because the message only pops up when I have second life opened up... I am typing this on the webpage and it is not happening and it also doesn't happen when i'm on imvu. I was having very odd things happen in the first few days that I created my account.. It was the glitching, the lag, and i also had my avatar running on it's own.. I wasn't able to control it much, that seems to have stopped but it's weird.. Please let me know if you find out what was the cause or if you're able to fix it..