Developer mode stops working

Hi All, I am facing an absurd problem with my Roku 2. I enable "development mode" in it and access the roku installer page. But after a couple of minutes I can't access the installer page. I have to disable 'development mode' and enable it again. I don't know why is this happening? Someone if could help me out with this, I would be so thankful.

Note: Roku is not disconnected in the meantime while the development stops working. And IP of the roku is same, I can still watch other channels. I just can't access installer page, or telnet it, not even ping.

thanks in advance.
Paras