calendar syncing with google calendar

I started a project with a client who uses Google Calendars.  When they send me an individual meeting invite, it syncs fine with Outlook (mac).  However when the send multiple invites for a series of events (not recurring) but have the same name, Outlook only accepts and syncs with one.  If I go and accept the second invite, it removes the first from my Outlook calendar.  My iPhone and Google Calendar still show all events.   How can I get Outlook to sync properly?