Problem in Deleting all the calendar entries?

Hi All

We are using a client-server application which notifies the symbian Client (N9300) about the appointments, meetings and his mail accounts.For this,the Symbian client synchronizes with a remote server and keeps the end user updated about his mails and meetings etc.
A problem occurs when we try to delete all the calendar entries from the default calendar application using 'Move/Delete' option of the  'Tools'menu.Now when Our application tries to synchronize this ,it does not let the default application delete the entries.

Morever,no problem occurs when only a few calendar entries(5-10) are there in the default calendar.This problem occurs when the calendar is having a number of calendar entries.

What can be the reason?How can we catch the event when the
'Move/Delete' option of the default calendar appliaction is selected?

Anybody having idea how to solve this problem??
Hope to get a reply
Thanks in advance