How to config a site_id from multy source

Hi everyone

I have a problem. Some channels that I defined for grasping in the config file, are unable to grasp one site. For example:

<channel update="i" site="m.tvguide.co.uk-full" site_id="349" xmltv_id="TG4">TG4</channel>

<channel update="i" site="m.tvguide.co.uk-index" site_id="349" xmltv_id="TG4">TG4</channel>

These are one channel but 2 site, and if I set both of them in config, the program will show me error: "Duplicate ...." but I need define some backup of each site. Could you help me, any solution?