John,

Your query doesn't work since VFP8 (SET ENGINEBEHAVIOR 80) and it's not a bug but behavior change. The changes are documented in VFP8 help under Behavior Changes Since Visual FoxPro 7.0 http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_foxhelp/html/fogrfbehaviorchangessincevisualfoxpro70.asp and in INFO: SQL SELECT Behavior Changes in Visual FoxPro 8.0 mskb #813361. One of the ways to get it to work is to use UNION ALL, if you don't need distinct records.

select IntergerField, MemoField from TableA;
union ALL select IntergerField, MemoField from TableB

>In eariler version of VFP the following works fine:
> select IntergerField, MemoField from TableA;
> union select IntergerField, MemoField from TableB
>In VFP 9.0 beta, the same code produces the following error message:
> "Operation is invalid for a Memo ... field.
>
>This appears to be a bug or a "by design" bug.
>Is this a bug?
>Has it been reported?
>Any thoughts?