OpenPSA 1.11.11 and iCal
There seems to be a bug iCal that manifests itself with OpenPSA repeating events. This might be reproduceable with earlier OpenPSA versions as well
To reproduce: Create event in OpenPSA, set it to repeat and subscribe to your calendar in iCal, watch as in month and week views iCal shows randomly some of the events (the .ics file contains all of them)
Watch more closely:

Here we have an example that shows that iCal knows there should be an event drawn on the wednesday (the "Openuser private" event is repeating on the same time from monday to wednesday) but it doesn't draw it, interesting...
Day view seems to work as expected...