It seems from my trivial Google searches, that some users find, for certain list types - an inconsistent experience related to modal dialogs.
In my scenario, we have a plain old SharePoint Foundation server, and on our particular sub site's Calendar, we have gone into 'List Settings' > 'Advanced Settings' and have turned off the 'Launch forms in a dialog' setting.
It seems to have no effect except for certain views of the calendar (we have a plain list view of the calendar -not by week/month/day or anything.. just a straight list rendering- where it does seem to work)
I'm wondering what's up with this?
For the meantime, I'm can use jQuery to deactivate the dialog functionality. But, it gets ignored if users click the left-hand calendar widget to jump to various dates (the ajax refresh kills off the DOM that was affected by my jQuery)