Youtube and BBC iplayer not working!?

Hey all. Hope everyone is well and enjoying the weather (assuming it's nice where you are )

I've been having a problem with youtube, essentially that the videos don't load. the website and the player and everything else loads fine, but the actual video itself never transfers (and doesn't even start to transfer/play). I DO have the latest version of adobe flash player.

Secondly, BBC iplayer keeps telling me that I need to be in the UK to watch it, which is strange because I live in London.

I've done a bit of self-diagnosis as it were. I KNOW it's not my ISP, because my flatmates who use their laptops to connect to our wireless network (as do I) have NO problems whatsoever with either youtube or iplayer. Which means that it has to be my laptop specifically. Secondly, when I went back home to my family over the weekend, I uninstalled then reinstalled firefox (my browser of choice) and youtube WORKED on their wireless network. This may tell me that it's something to do with how my broswer uses my ISP settings? i have no idea to be honest. (I didn't check bbciplayer at the time). I tried uninstalling and reinstalling firefox at my flat (where the problems are happening) but the problems remained, unfortunately.

I have also tried to play vids using IE7, but that has the same problem.

I'm stumped. This problem has been going on for about 2 weeks. Any help or advice or little tricks I can try to make this work would be much appreciated! thanks! :T

ps, I've also tried deleting temp internet files, cookies etc etc and nothing works. I also downloaded cccleaner (a free cleaning program i found on the web) and that hasn't worked either.. hmmmm