Videos barely buffer in Safari and Facebook using wi-fi on iPhone 5 but are fine on the YouTube app/m.youtube.com

Hey guys,

Really odd issue I've got but it hasn't fixed even after replacing my phone.

Basically I have a very good connection at home with a very good router (Asus RT-N56U). When using the 2.4ghz band I get speeds of upto 50mbps on the speedtest.net app and upto 80mbps when using the 5ghz band. When downloading from the Apple store or watching youtube videos using the app or going m.youtube.com I reach those speeds yet when I try to watch a video on facebook or a video on safari (such as on dailymotion, just to test), I can barely buffer more than 3 seconds of the video before it pauses. When checking the traffic manager on my router, it shows that I'm only downloading at around 30kB/s, an unnacceptable speeds.

My old iPhone 4 did not have this problem and loaded all videos well, even though my browsing experience was considerably slower (but still fast). If I turn off wi-fi and use my 3g connection (stupid provider doesn't have 4g yet), my browsing experience is slower but all videos load well enough to buffer without pausing.

I have no idea how this could happen. I highly doubt that the iPhone 5 uses some different connection to load videos (and not all data) to the iPhone 4 which is incompatible with my router AND somehow Youtube has managed to bypass this error. I have not tried many routers and AFAIK they all have this problem but today when I was at the apple store facebook videos seemed to work fine (but they were very short and on my net sometimes videos buffer alright for very short videos).

Any ideas? If you need more techincal details, ask me what you need and I'll try provide as much as I can. I really don't want to change my router as it is really good and I doubt I will but knowing that it's simply my router would give me some comfort.

Thanks