I've spent the last day tracking down a problem with a jquery ui dialog and finally tracked the problem down to the version of jquery I was using. If I use jquery v1.4.1 with jquery ui v1.7.2, my dialog open with effect slide opens but then immediately disappears. If I use jquery v1.3.2 the dialog works just fine. I've been unable to find any stated requirement for which jquery version is supposed to be used with jquery ui. Is there a requirements list somewhere? I did notice that it appears that jquery ui v1.8 works with jquery 1.4 according to the the v1.8 release notes.