Delayed-goals

Hi,

Can anyone help me on the following?
I've a call to a goal that creates variables, imposes constraints, and tries
to instantiate the variables (in sum a normal search program). Strange is
that, after a successful goal call eclipse maintains a lot of delayed goals
related with the constraints imposed inside the goal. Is this behaviour
normal? Shouldn't eclipse free all the memory?
There is any way of clear the memory?

I thank in advance the help?
Best Regards
Nuno Gomes