>I can't Date Editor in the recent SVN revisions of GRAMPS because
>when I try to close its window, no matter if I press OK or Cancel,
>another empty window with same title "Date selection" appears and
>the program freezes. On Windows python even crashes. Editing
>date in event reference window works properly.

I see the same problem. Feel free to file an issue on the tracker.

>I also have one question regarding the new database format in
>GRAMPS. Are the changes made to the database not saved
>instantly as they were in version 2.2? I've found it a useful feature
>of 2.2 because my data wasn't lost even if the program crashed.

I'm pretty sure that if you change a value in a dialog and click "ok", it will save the change in the database.