Internet disappears after 5 min of work with my WDH1NC10000N

recently i’ve got problem : i turn on my 

Western Digital 1TB My Book World Edition WDH1NC10000N

it is connected to Linlsys wireless router. After 5 min or work my internet connection disappears, i do not even see my wireless network availability. When i press button on Hard drive to turn it off - internet comes back withing 2 minutes. Anybody had problem like that ? HELP

I have Win 7 x64 … if that would help