dialog close callback

Hi, thanks for the help I've received so far.
I'm using a dialog, and I'm using a callback function for close in
order to manipulate within the dialog. Doing this, however, has cause
the dialog to not close. It will close for a fraction of a second,
then open again. I've tried returning true, false, and no return
within the function, to no avail. I'm using UI 1.5.1 and jQuery
1.2.6.
Thanks,
Brent