In Our case we developed online module booking program as Webdynpro using SAP delivered HRIQ_STUDENT_BOOKING
but we have following symptom that can not understand.
1) for SE available check we use V_piqsmbooked table.
2) Student see there is available seats and trying to bookin but system send error message saying " there is no available seats
in the event package" but when i check V_PIQSMBOOKED table there are still available seats.
3) this situation only happen not the starting time of module booking but normally when there are few seats(5 availavle seats) available and compttition is very high.
4) finally booking is finished successfully but some of the student meets error message that saying " no seats available in SE.
5) if somebody meet this kind of situation, please recommend what i have to check.
Did you look into "Buffering Duration for Availability Check in Module" in IMG?