Primavera P6 Activity Notebook not saving edits

Hi hope someone can help.

I've recently installed P6 R83 with Oracle database, and it all seems to be working. When a user adds an activity to a project, he/she can add navigate to the Notebook tab, add a new Notebook topic and enter text using the built in HTML editor. A new entry is created in the TASKMEMO table and the text is saved as a blob.

So far so good.

However if a user goes back to an existing Notebook topic and modifies the text, its not saved to the database. There are no errors generated, just nothing happens. As soon as the user navigates away from that topic the new text is lost.