Also make sure you are trying to listen to it within the Designated Operational Coverage (DOC) range. Outside those parameters then there is no guarantee that other stations will not be using the same frequency.
Unfortunately the AIP only seems to give these DOCs for Navaids and not for voice frequencies. A European general standard for Arrival ATIS seems to be up to 20,000' and within 60NM of the ATIS facility.
Maybe someone at MAN can provide us with the specific info for their frequencies ??