[gnome-db] "maximum cursors opened" in oracle

i have a program that read from a db oracle and write to a portgresql db

in oracle settings i see that i can open 900 cursors; that program  
reach the maximum and it doesn't execute more queries

i'm quit sure that i unref every gdastatement and every gdadatamodel

what could be the problem?

i tried also using with gdadatamodeliter but with the same result

thanks in advance