browser/streaming video/ network probrem

hello, my name is chris.

i have recently upgraded my machine.

Windows 7 Home Premium x64 (inc Service pack 1)
Asus Crosshair IV Formula
AMD Phenom II 1100T x6
Corsair Vengeance 4x 4gb 1600mhz
XFX Radeon HD6870
2x WD 20EARS 2TB Sata drives
1x sata HP 107d
Netgear DG834PPN Wireless Router (Connected via LAN)
(using ie9 and chrome)


The Problem:-

on both IE 9.0 X64 edition and Google Chrome (both with up to date flash video software.
Streaming videos, it starts playing brilliantly.

eg:

- OPEN Youtube video
- Loads fast and starts playing
- watch for 5 seconds
- skip video ahead 2 minutes.
- Loads fast (almost seemless)
- watch for a minute
- skip ahead another 2 minutes
- Buffer time is getting longer.
- watch to finish
- close page

- OPEN new Youtube video
- Loads slowly
- watch for 5 seconds
- skip video ahead 2 minutes.
- Loads very slowly
- play for a minute (jittery)
- skip ahead another 2 minutes
- Video doesnt play.
- Close page (no obvious programs using the network)
- Routers'traffic' lights are extreamly active (both internet and connected lan port)
- Downloads, browsing, p2p, streaming all slowed to a crawl or no-existant.
- During this, Speedtest.net - The Global Broadband Speed Test says 0.9 Mbps download speed or less.
- Physically Disconnect LAN connection and wait for 10 seconds.
- Reconnect Lan
- Everything goes back to normal

- Sometimes before disconnecting the lan i wait and eventually the lights slow down to idle and works as normal

- repeats 2-3 times then system wont even recognise that it is connected via lan to anything.
- Restart machine
- Some times hangs at 'windows is no closing'
- Loads up
- Sometimes microsoft internet explorer data isnt remembered. like passwords.

Speedtest.net - The Global Broadband Speed Test
my standard Download speed - 1.8 mbps
during problem - 0.9 mbps or less
after (without disconnecting) - 2.25 mbps ???

my question, how do i stop this persistant irritation?

thank you for you time and patience

ps i have also had this issue

annoying usb net drop no complete shutdown error

i believe it is somewhat connected to this issue.

bump

i know all drivers are updated, but i have to be honest with you. I dont know what a gateway server is. How would i find out if i am using a gateway server?

thanks for the posting by the way ;-)

turns out it was BitDefender Anti-Virus 2011. when i removed it, video streaming working very well. i have started using kaspersky Anti-virus 2010 and video streaming has not been hindered