DejaCal and iPhone Calendar app don't match

[dejaroy]

I am using Companionlink to sync my calendar from PC (Lotus Notes) to iPhone (DejaOffice). I notice there are some appointments in DejaCal which do not appear in the iPhone Calendar app - why? It seems DejaCal has all of the appointments, but there are some missing in iCal, and I can't see any pattern to the ones which are missing.

iPhone 4S IOS 5.0.1 Verizon
DejaOffice v1.2.11
CompanionLink build 5020
LotusNotes 8.5.2FP2
WiFi Sync

Thanks in advance,
Roy Lambert