Multiple invitations on iphone/ipad

I started seeing some off behavior.  If I accept a meeting invite on Office for Mac 2011, my Office 365/Exchange calendar gets properly updated.  I sync my iphone or ipad and I get requested to accept or decline the meeting invite on the device as well.  However, if I accept the invite on my device, Office for Mac 2011 gets updated properly and I do not have to accept the invite a 2nd time.