On FF, I notice that if I allow the website to choose it's own fonts; vbulletin forums don't have unread threads in bold (see attachment).In the attachment, all those threads I have not read. If I tell for FF to use the fonts I have chosen then forums behave as expected.
I also using chromium (from the fedora-chromium repo). I am faced with the same problem. However I cannot find a way to change the behaviour. Anyone with any ideas?