Access 2007 Update Query problem

DeDoc

So, I have a table and I want to update several records in that table. To identify the records I need to update I have a query.

e.g.

UPDATE My_Table
SET My_Table.Field1=1
WHERE My_Table.ID IN (SELECT ID FROM My_Query)

My query is identifying the appropriate records, and by using various alternatives (joins etc) to the above I can get the query to display the appropriate result in the 'view' screen, but when I try and run the query it gives me an error "Operation must use an updateable query"

e.g.

UPDATE My_Table INNER JOIN My_Query ON My_Query.ID=My_Table.ID
SET My_Table.Field1=1

I've tried using a DLookup in the criteria instead of the sub_query, but that returns just a single result.