variable total integer

Using Dialect 1 .. select sum(total) as total -> Rave reports comes thru as
a dtInteger, as expected.

Using Dialect 3.. select sum(total) as total -> Rave reports fails on
'expected fieldtype dtInteger but found dtInt64

However

Using Dialect 3.. select cast(sum(total) as integer) as total -> Rave
reports accepts as a dtInteger and all works again

Ant Idea's ?

Thank you
Hans