Ive had stacks of emailed questions recently on strange behaviour for external appointments from Outlook through Exchange. At present, because there is still no Exchange CDO patch, appointments sent outside your organisation and accepted by the external party will come back and hour (or more) out of sync with your appointment. This is known and even affects those with the Windows DST patch applied or manual setting of the timezone to GMT+9. This is because Exchange maintains its own internal tables for DST.
Until the patch is released for Exchange this will continue to be an issue. At present you have two options that I can think of:
1. Educate your users (I know I know what youre thinking...:) ) to not send external meeting requests for the time being until you notify them that they can
2. Again educate your users that if they must send out an external meeting request that they should enter into the body of the meeting request the actual time they want to meet so that the user on the other end can manually shift it to the correct time in case theres confusion.
Again we apologise for the delay in getting this patch ready for you. It is being escalated and we hope to have a resolution shortly.