Bare with me here, and if my case is just a fluke then please tell me, but.

Until recently (about 2 windows updates ago) I could watch videos on my computer problem free. However, now I will have a video, FULL SCREEN, streaming online and my screen saver will pop up. I mean WTF before I could watch a video, no matter how long it was on the web, not full screen and that pesky screensaver would behave, never would have known there was on set, and now i comes up mid video. Seriously the only computers that would do such were the computers at my school, and now my laptop does and I didn't know if I was a special case or if there might be some setting that have been/could be changed, or even if anyone else might have had similar experiences.

I'm on Sony Vaio FW-490J
Windows 7 64-bit SP1
I switch between Chrome and IE9