Unfortunately I can only go on in the evenings, or earlier in the morning. You might want to go to the edit tab and check preferences. There is another menu within that called graphic settings (i think) Perhaps they are set way too low. I cannot access the program right now, but I believe there is a switch that toggles between 4 different levels of quality. Select a higher level of quality, quit out of the program and reenter. The lowest level sets avatar quality at a very bitmappy feel, and maybe this can help. Although even at that level, the graphics shouldn't be doing what is happening to you, it is worth a try.
There are more specialized graphic settings (a more button or something like that) but I would have to be there in order to guide you through those).
There are more specialized graphic settings (a more button or something like that) but I would have to be there in order to guide you through those).