Guys video playback might be more general problem than in the browser:
With videos also, on Gallery’s Video player, when I play videos in several formats, some times video doesn’t start play and the app crashes. Surprisingly when I restart the app and go play that video it plays like nothing happened. This is happening some times after 2 - 3 videos played up to 30 - 40, or could not happen at all.
For me problems appeared on xperia 10ii, with xperia X was okey, when (very few) videos weren’t playing I could scroll up / down on the app, push play again and then it was loading / playing. On Xperia 10ii video playback is unreliable, and I am wondering if I am one of the few people experiencing this.
Let me know if you want me to file a new bug report for that.