reboot your modem, unplug it for like 10minutes so it gets a full reset on the provider and get new values.
reboot your computer aswell
check for any new installed stuff like google bar, chrome bar, radio bar, bing bar, etc.
check for pando media booster, delete it if u have it
open cmd
type
ipconfig /flushdns
delete cookies, temp files, etc.
let us know if still persists but if it does...might be some virus interrupting your connections.