(This has subsequently been solved by an update to Opera.)
Having upgraded to the latest version of Opera (stable) on Ubuntu 14.04, I have encountered a seemingly insurmountable issue with rending the page for the bookmarks. Possibly related to this, the bookmarks pop-up menu appears blank.
The menu is interesting because though it appears to be empty white space, you can click items in the menu if you can guess at their invisible locations. Very much unusable but interesting nonetheless.
The bookmarks page (Show All Bookmarks) however is utterly useless. It is true that one could make guess about locations of invisible items on the page, since the page is very much larger than the pop-up menu such guesses seem profoundly unlikely.
The bookmarks page itself… well, have a look.
The echo is live on this top row (the echo repeats down the page but I only included the top here). You can see that on the left I have clicked into the address bar, and the echoes have also highlighted the contents of their address bars.
Not sure what can be done at this point. I am opening a thread over at the Opera forums. I’ll keep you posted.
Looks like this is only an issue with the xorg (open source) driver. If you are able to switch to a current proprietary driver you may be in good shape.
As you can see I am now using the most current NVIDIA proprietary driver and no longer using the X.org driver.
It’s also broken in other OS’s so there you have it.
Hope this helps.