When you set your tv client to "Select channel by index" and enable "show channel numbers".

Expected result:
The guide shows the index of the channel. The index is what you use to tune.
Actual result:
The guide shows the configured channel number of the channel. This is however to no use when using the select by index option.

See here: http://forum.team-mediaportal.com/improvement-suggestions-46/display-incrementing-channel-numbers-epg-page-83784/