Cam you post a screenshot?
Have you tried another browser in Ubuntu? I have a vague understanding of your problem but maybe it's a font issue.
I tried firefox, chrome and opera and they all do it. I think it started happening after I attempted to install ff 3.6 and messed up the software sources list. I fixed that but in the process of trying to fix it while asking around in forums it started happening and has been happening ever since.