For some time I have had the problem that certain text characters are substituted by boxes: it depends on the site (but this is one of them, and I have to use Firefox to use it). I wish I could attach a screen shot, but I can't. In a nutshell, the base discussion page (which lists discussions by title) - got by clicking on Discussions in the previous screen - apart from the advertisements and "start a new discussion" (on the right) consists purely of boxes where text should be, except for the title "Discussions" and member usernames, which are rendered correctly, so is quite unusable.
The bbc.co.uk home page is a mixture of readable characters and boxes, to give another example.
Secondly, certain web addresses, such as http://www.opera.com/o/news-portal produce a page consisting entirely of seemingly random Chinese characters (I checked: Google Translate manages a few words here and there) covering the entire page on a green background, rather than a message (in this example) that news portal is now closed.
I'm using Opera 12.16 for Linux i386 on Ubuntu 14.04LTS, and any suggestions are welcome.