I have managed to achieve the correct results - by starting again and not using the WA extension!
The recordset is:
SELECT PgID, UnderPag_PgID, PgTypeID, SiteID, PgDate, PgTitle, PgMainPic, PgMainPicAltText, PgMenuTxt, ModifiedDate, EvStDate, EvEndDate, DisplayUntil, RotYr, MemOnly, MemID, PgDesc, PgKeywords, PgSortOrder, ContactEmail, AllowComments, PgHits, PgDetails
WHERE (SiteID = WADASiteID AND MemOnly = 'N') AND (((PgTitle LIKE %var%)) OR ((PgDesc LIKE %var%)) OR ((PgDetails LIKE %var%)))
with the var='searchtext' parameter.
Thanks for all your efforts and pointing me in the right direction' I had tried a similar approach initially, but obviously had the syntax wrong.