Batch Register participant to an event results in only last contact being added added to event

Hi,
We have installed civicrm 3.0 from svn revision-23161 & drupal 6.13
While adding multiple contacts to event using contact search form, only last selected contact present in the search results is getting inserted in event.

Here are the details to reproduce the problem.
1. Go to contact search form, search for contacts of your interest & select contacts.
2. Now from "more actions" drop-down select the option "Add Contacts to Event" & hit Go (attached - participant_batch.png)
3. Now select an event from event list & set the status to Register & hit save (attached - event_selection.png)
4. Report page shows that all participant are added to event & notification is also sent. (attached - report.png)
5. I checked my mail queue, notifications are present there but on event page only one of the contact is being added to event (attached - event_dash.png)
6. also participant listing for that event shows only one record. (attached - participant_list.png)

can you please check the problem.

thanks,
Shashikant.