A bug has been identified related to the HD2 calendar. When using the Calendar tab of HTC Sense and selecting Week view, you are not able go past the week of 26th October - 1st November 2009.
This means there is no way of using Week view for looking at this week's appointments (15th November - 26th November 2009). This happens when users have Monday selected as first day of the week, but the bug disappears when first day of the week is set to Sunday.
This seems to have originally been reported by a Dutch user, but has been confirmed by users over at xda-developers. Cooked ROMs seem to also have the issue.