If you have a comment attached to the code with substitution variables, Toad returns the 'ORA-01858: a non-numeric character was found where a numeric was expected' error upon using the Execute Statement (F9) or Execute Snippte (Shift-F9) commands. If you have no comments, it works properly.
WORKAROUND:
Use '/*...*/' instead of '--' characters to include comments in the code.
STATUS:
Waiting for fix in a future release of Toad for Oracle.
