Default numeric scale of zero in JDBC?

Hello,

I have discovered that the jdbc driver apparently uses a default scale of zero decimal places for SQL numeric
operators,including the sum() aggregate operator.  For example, this query: 

select (1.5 + 2);

This returns 4 from jdbc, but it returns 3.5 when run from within PGAdmin.  The only way I can coerce the value to
returndecimal places is to explicity cast the value to a numeric with scale: 

select cast(1.5 + 2 as numeric(10,2)) as value

This returns 3.5.

Also, queries like "select sum(value) from table" returns a rounded value, even though the column 'value' is
numeric(16,2). Is there a magic vmparam or setting to default the precision at the jdbc driver level?  I am trying to
runa large existing system on PostgreSQL and it is not feasible to hunt down all numeric operations in thousands of
classesto explicitly cast them.   Have others have encountered this issue? 

Thanks,

-Todd