problem with collection

Hello,

I'm trying to update my class but it does not remove removed items  
from the collection. So, when I add new items to the collection, in  
DB there are copies of those old instances. So, when restarting  
application, it fetches too many instances (old ones and new ones).

May 17 15:50:33 kanta1 postgres[17491]: [113-1] LOG:  statement:  
SELECT 1
May 17 15:50:33 kanta1 postgres[17491]: [114-1] LOG:  statement:  
UPDATE ibiz_invoices SET global_id=397,client='xxxx
....
May 17 15:50:33 kanta1 postgres[17491]: [114-7]   
12345-67890',order_description='',payment_terms=35,notification_time=8,i 
nterest='9.500',notification_payment='10.00' WHERE id =
May 17 15:50:33 kanta1 postgres[17491]: [114-8]  39
May 17 15:50:33 kanta1 postgres[17491]: [115-1] LOG:  statement:  
commit;begin;

This only happens if I have first created the original object and  
then tried to update it. So if I restart my application and try this  
again to same object, then it removes references.

code:

dao.begin();
ibizobj.setId(id);
ibizobj=dao.retrieve(ibizobj);
col = ibizobj.getOrderItems();
// col == java.util.Collection
print (col.size()); // outputs 5
col.clear();
print (col.size()); // outputs 0
dao.update(ibizobj);
//nothing is deleted from db

dao-code:

dao.update == broker.store(bean, ObjectModificationDefaultImpl.UPDATE);

repository:

<class-descriptor class="com.intertechnika.ibiz.invoices.Invoice"  
table="ibiz_invoices">
...
  <collection-descriptor name="orderItems" auto-retrieve="true" auto- 
delete="true" auto-update="true"
			element-class-ref="com.intertechnika.ibiz.invoices.InvoiceItem">
   <inverse-foreignkey field-ref="invoice_id"/>
</class-descriptor>
<class-descriptor class="com.intertechnika.ibiz.invoices.InvoiceItem"  
table="ibiz_invoice_items">
...
  <field-descriptor name="invoice_id"	column="invoice_id"	jdbc- 
type="INTEGER" access="anonymous" />
  <reference-descriptor name="invoice" class- 
ref="com.intertechnika.ibiz.invoices.Invoice" auto-retrieve="true"  
auto-update="false" auto-delete="false">
    <foreignkey field-ref="invoice_id" />
  </reference-descriptor>
</class-descriptor>

Only thing that seems to work is to do it like this:
dao.begin();
ibizobj.setId(id);
ibizobj=dao.retrieve(ibizobj);
col = ibizobj.getOrderItems();
// col == java.util.Collection
//PSEUDO CODE STARS HERE
foreach orderItem do dao.remove(orderItem);
//PSEUDO CODE ENDS HERE
dao.update(ibizobj);
//nothing is deleted from db

Using ojb 1.0.1 and java 1.4.2

I tried to look from release notes that if this is a bug that is  
fixed, but did not find anything.

Thanks,

Joose Vettenranta