>The RecordSource for a grid in the same form is based on a p-view on the table DETAIL. The default value for the idMaster column that links the two tables was set using DbSetProp() as MASTER.id. Note that it si not mt_MASTER, just the plain table name

Silvio,

I would bet that setting the link column to Databasename!Master.ID would not fail. However, I woudl wonder what the from clause looks like, if it is

FROM Master mt_Master JOIN ...

then that would suggest why the later ref of Master fails, the SQL is using a local alias of mt_Master and knows nothing about any alias of Master.