I occasionally have the problem with Spaces (in both 10.5 and 10.5.1) where active windows for an application stop showing up; this seems to be a bug with Spaces. One solution has been to disable Spaces and re-enable it. But using the scripts from this earlier hint, I can use the "Collect on Current Space" script to get all the windows to show up in whatever space I'm in, regardless of whether they would show up before.

This is a real lifesaver when unsaved changes are in a window that won't show up.