the bug is that the 3rd pane of calendar (agenda view?) won't display an event more than 39 days ahead. You can see your event 4 months ahead if you use the 1st or 2nd pane of calendar and browse to that month/day but in the 3rd pane which lists upcoming events its limited to 39 days' ahead events only.

I remember a work-around for this being posted but unable to find it right now. Will update this post if/once I find it...