Possible SQL Select glitch!!!

Hello All...

I have encountered a funny situation in the select statement with
Paradox tables
Using BDE16... Here goes:

        Select          MyFirstField, Sum(MySecondField)
        From            MyTables
        Where           MyFirstField in (1,2)
        Group By        MyFirstField

On such a statement, the engine returns "capability not supported"
If I remove de "SUM", and the Group by section... no problem, all is
well but I
don't get what I want.

On the other hand, if I add the criteria "1=1 and" at the begining
of the statement as such:
        Select          MyFirstField, Sum(MySecondField)
        From            MyTables
        Where           1=1 and MyFirstField in (1,2)
        Group By        MyFirstField
guess what... IT WORKS!!!

I know that the same problem occurs with BDE32 but instead of returning
the message "capability not supported", it runs and returns a false
result set!!!
It's even worse than BDE16.

Does anyone know if it's a problem or the syntax I use to build my
queries.

Any information would be appreciated... Thanks in advance

Bernard