O.K,
Had a read back through the workbook over breakfast.
I found three references to area frequencies.
The first was in the question: What is meant by the term SARWATCH?
My answer: Putting in a flight plan which details E.T.A.(must be canceled either on the area frequency prior to leaving the boundary or by telephone)
The second: What are the minimum calls required by a microlight outside Controlled Airspace?
My answer: As per question 12.5 (that was CTAF and CTAFr stuff, not relevant to this), as per VMC criteria, if we go above 5000' must advise location if requested to speak by air traffic services or other aircraft.
The third was found in the aviation maps and publications section: List four features of the information contained in the following maps.
b) ERC (Enroute chart)
My answer: Commonly flown routes, controlled airspace, major airports, restricted and danger areas. Instructor adds also shown Radio Area Frequencies, sport aviation use and cruising levels.
Looking back I suppose I should have questioned those things I obviously didn't understand/ hadn't had explained. But without the knowledge of the existence of the Area Frequency I can find several ways of explaining what I must have thought the above to mean.
In summary I would have to say it is a partly a HGFA problem and I have to take some blame myself for not questioning the references to Area Frequencies (the way I justify this to myself is that I must have thought area frequencies and CTAF's were the same thing (might help me through the day anyway:Flush:))