Time shifting in my calendar - any suggestions?

Hi,

I faced with following problem with time shifting of events: some of events were shifted one hour back. From Why is the time on my calendar events shifted? I understand that the problem is known and was already corrected, but some of events is still shifted.
After small investigation I noticed that only all-day-events are shifted to "yesterday 23:00" and till "today 23:00". In this case 3-4 all day events looks terrible, moreover, these events are moved to previous day and takes 2 following days.

What can be done?

Of course, any suggestion to manual fixing is rejected [img]/images/graemlins/wink.gif[/img]

Thanks for help.

P.S.
All events in WEB interface are OK.
The problem is occurred only for downloaded events from server.