Unable to edit XML data in Schema Browser | Tables tab | Data Grid with an Oracle Client 10.1.0.3.0 or higher.
Warning message is displayed when selecting View | Options | Data Grids | Data and un-checking the "READ ONLY" option for XML Popup Editor:
"With a client version of 10.1.0.3 or 10.2.0.1, the XML editor has a known issue: data is truncated when you try to post a change. It is not known if a later version of Oracle will resolve the issue. Do not uncheck this unless are sure it's OK."
If user tries to modify or add data, the data field is truncated.
Issue with the ODAC. At the time 8.6 was released, it was not known if the issue was with Toad or Oracle.
Issue fixed in version 9.0. The latest version of Toad for Oracle can be downloaded at: http://support.quest.com/support_download/Downloads.asp