I have updated Wordress 2.5 to 2.6 last night and now when I click on a single photo from a gallery the thickbox will not load. The image will load in a new window instead of the thickbox.
I am also using ms_lightwindow plugin for my YouTube videos. It has not caused a conflict before, so I don't think it is now since I can disable the ms_lightwindow plugin and thickbox still does not work.
Please see example here:
NextGEN Gallery 0.98