I have what I think is a similar problem. And odd as hell.
We have an event calendar for which I created a custom event date field. For one particular entry, which should be set to 7pm, it won’t take the change but stays at 8:00pm.
To make it even stranger, it will let me set it to 6:59pm, but if I used 7:01pm, it changes to 8:01pm. Huh?
It must be a DST issue because it happens to be on 3/7/09 which is the day before we switch, but I don’t know how to make sure that one entry is OK without messing with any others.
There’s an event on the very next day that works fine.
I have nothing in the Server Offset field, “no” selected on Daylight Savings Time” and “yes” selected on “Honor daylight savings…”