I've not had these issue recently, but i had similar ones a while ago. What is the graphic card type you have, is it ATI or NVidia, also are you on MAC or PC. That would help to understand more your problem.
Also did you tried other viewer, such as Phoenix for instance, maybe they have a different way to handle your graphics.
I would suggest you as well to go to the Jiras and seach some of the issue you seem to have, http:/jira.secondlife.com
I know searching in the Jira can be sometime a pain but usually you find what your looking for with the right keywords. Plus looking there, if you add your comment on your issue, it help make the viewer better at the end of the day