DVB-T systems do vary around the world, but if the broadcaster provides an EPG (as distinct from providing only "now and next"), the minimum that he could provide for each MUX would be the EPG for all of the channels in that MUX. If that were the case, you would need to select one channel from each MUX in order to receive a full EPG. (Not necessary in the UK, since each MUX contains the EPG for itself and all other MUXes.)I just unticked them all except RTÉ One and did a rescan. All EPG listings appeared as usual .
Your screen shots show relatively few DVB-T channels. So few, in fact, that they could probably all be contained in a single MUX (depends on how much compression of the datastream the broadcaster uses). So perhaps Ireland has only one MUX.
Finally, the DVB-T radio channels are part of the MUX too. So I think that you could deselect all radio channels. This seems counter-intuitive, but the radio EPG will be grabbed at the same time as the TV EPG, from the MUX containing the TV channel that you have selected ("RTE One"). I mention this as I wasn't sure whether you had changed your radio selections as well as your TV selections.
-- from CyberSimian in the UK