Remember dialog sizes or not?

A lot of program dialogs can be resized. Some programs remember the new size of the dialog after you've resized it. So next time you open the same dialog, the new size is being used.

Right now in the software I'm designing for this is not the case, the dialogs don't remember their size. I've discussed it with a colleague and his stance is that users often do this temporarily just to view things that are truncated or fall just out of the dialog. I think that resizing the dialog is a conscious action by the user who is not happy with the default dialog size, and that it should be remembered.

I'm wondering if there are any guidelines on this on what would be best practice?