Remote calendar events not showing for >2 months

[quayce]

I have set up two Plans 7.6.1 calendars on different domains, and linked them using the excellent Remote Merged Calendars feature. This is working fine with the following exception:

When a user displays more than 2 months at a time, the remote merged calendar shows events for only the first two months. For example, if I start with March and select 5 months to display, the calendar will show remote merged events for March and April, but no merged events for the following months.

It doesn't seem to matter on which month I start, or for how many months I want to display; the max remains two months of remote events.

Example URL: http://atasc.org/cgi-bin/calendar/plans.cgi?cal_start_month=1&cal_start_year=2006&cal_num_months=4&cal_id=8&display_type=0

URL for the calendar being used as the source for the remote events:
http://octaa.org/cgi-bin/calendar/plans.cgi?cal_start_month=1&cal_start_year=2006&cal_num_months=4&cal_id=8&display_type=0