It seems that you are having some issues in order to control the Slingbox and the TiVo attached to it, since the virtual remote control does not respond.
The first step to follow is to verify if the IR Blasters are working in a proper way. With this in mind, I encourage you to check the following links:
If the IR Blasters do not work, I encourage you to contact us as soon as possible. We will offer you the option to get a replacement if the IR Blasters are damaged.