I seem to have the same problem described by Vladimir. I noticed it in two cases.
One of the events was set previously as an "all-day-event" on a Sunday (25th March to be exact), but after importing it from the previous version on Rainlendar (0.22) it showed up on the day before, Saturday 24th March. But the real problem is I cannot change the date to Sunday anymore. I can set the event to whatever date I wish, except for the 25th. I also tried deleting the event and making a new one, but the problem persists: I choose the date as 25th March and the program saves the event to the 24th March.
I've had a similar problem with an older, recurring event. It was imported correctly, but after changing the text, it was saved to the day before. The event was originally on the 26th March 2000, but got modified to 25th March 2000. Same problem as before here, cannot set the correct date, even after deleting the event. Creating and changing events with other dates is no problem.
Another thing I noticed is that, before the 25th March, single-day events after the DST date appear either as two-day long or on the previous day.
My time zone is also GMT +2 Romania.