In version 22.214.171.124 Toad saves historical, named and personal sql as an XML file - savedsql.xml. Problem is if you execute sql statement creating xml syntax it will break the file. The xml tags in the saved sql statement will then be read as part of the xml tags of the savedsql.xml file causing the syntax to be corrupted. Since Toad is unable to properly read the xml file, it will not show any saved,named or personal sql anymore, although it will still write to the file toad is unable to read it back.
Waiting for fix in a future release of Toad for Oracle.