Old thread, but same old problem on a new box...

Can't seem to get the EPG to refresh for the following channels if I let CrossEPG update daily - so after a week these channels would have no EPG. However, if I delete the epg.dat file and do a new download the EPG will update. HD channels include:
- Channel 4 HD
- CNBC HD
- CNN HD
- Al Jazeera HD
- LoveWorld HD
- Record TV HD
- Iran International HD
- Sky Intro

Not sure if the above channels share something in common.