Reseting the due date value of a work items from web ui sets the due date to 1st Jan 1970

 Environment
Rational Team Concert 4.0.0
Web UI

How to reproduce
Open a WI that has a Due date in the Web UI. I used IE 8
clean the value of the Due date ---> empty field
Save the Work item ---> Due date becomes '1 Jan , 1970', see attachment 119257
Open the same Work Item in the eclipse client, the Due date is set to '1 Jan , 1970'
The history shows the wrong date as well: Due Date  24/10/2012  →  01/01/1970

What is:
The due date is set to  '1 Jan , 1970' when user removes the value
The history should show Due Date  24/10/2012  →  Unassigned or None or empty
The date is wrong, this is data corruption. A Due Date in the past is not meaningful

What should be:
The due date should either be set to None or empty

How it works in the eclipse client:
Open a WI that has a Due date in the Eclipse client
clean the value of the Due date ---> value is set to None
Save the Work item ---> Value is still on None
Open the same Work Item in the Web UI, the Due date is empty

The behavior of the eclipse client is fine.