This is akin to the scaling issue.
If something is SUM'd (or presumably any SQL command that performs arithmetic) and the value exceeds the scale (precision) of the target variable, in BDS the code continues and in Genero the program aborts with a precision error.
The problem was noticed on SUMs - hence its use in the example below (I know it's not necessary ;-)).
IE code extract:
DEFINE l_total DEC(8,2)
...
SELECT SUM(1000*1000) INTO l_total
FROM some_table
DISPLAY 'Got Total (',l_total,')'
