I tried your link and the videos, initially, would not play. I remembered Opera Turbo was enabled. After disabling, the videos played normally. There are other videos that will not play nice with Opera, turning off turbo just happened to work here.

Same problem here with certain websites, example oregonlive.com (other city newspapers use the same format).
Refreshing page usually clears the problem. Tried on my dad's Windows 7 computer, same problem at times.
No issues using Firefox. (Default settings..both computers). Both are older computers. Will play with hardware acceleration, java script settings and see what happens.

Problem solved: For my system, uninstalling, including checking the box to 'Delete my Opera user data, and doing a fresh install solved the problem. The issue was a corruption of my Opera user data (see previous post). Bookmarks were saved to a html file. Cheers!

The theme problem, always reverting to 'Raindrops, continues in 33. To test further, I installed the Developer and Beta versions of Opera. The problem does not exist with these two. A reasonable assumption is something in my settings, or something from continuously installing over the top, with Opera stable has been corrupted.
However, I'll give stable(34) one more chance when available. If the problem does not clear I will start fresh with a complete and thorough uninstall. I'll post an update on the results.

Problem continues with Opera 33.

I've blocked auto updates via my firewall. Works very well.

Have the same problem with Opera 32 using Windows XP Pro SP3.
If I close and re-open Opera, whatever theme I saved will go away and the default Raindrops theme will appear.
If I save one of 'My Themes', close Opera and shutdown the computer, the theme saved will return upon re-starting the computer and opening Opera. Of course, if I close Opera during the session and re-open...Raindrops again.

Have had the same issue with Online Armor firewall. Started with 29, went away with 30, but came back with 31 and 32. With OA enabling 'Learning Mode' for one opening of Opera after install seems to fix the problem.

XP problems resolved. There was a conflict between the newer versions of Opera (30.0.1835.125 and the Betas) and my firewall, Online Armor. Problem was discovered with an attempt to load the latest Beta. Result was same as before, 'Out of Memory' error. This time I disabled the firewall and tried again...success! There's was nothing in the firewall configuration to indicated a conflict. Everything looked normal. Re-enable the firewall and tried opening Opera Beta again..same problem, so I added the Beta file to 'Exclusions' and the browser opened properly. With the browser left open I removed the Beta file from the exclusions, closed the browser and re-opened. Everything runs fine now.
I repeated the process with Opera stable and Opera 30.0.1835.88 updated properly to 30.0.1835.125.

We'll see if the conflict continues with the next update. At least there's a work around if needed.

Tried again...same 'out of memory' message. Tried the new Beta, same problem.