WORKAROUND
1) Find the TOAD_SPACEMAN package in the schema where you installed supported objects
2) In TOAD_SPAMECMAN package edit the procedure CAPTURE. Please comment the following DELETE statement:
/* DELETE PRE-EXISTING DATA FOR CURRENT DAY */
--DELETE FROM TOAD_TABLESPACES WHERE MON_DATE = V_MON_DATE;
Then recompile the package and let the Toad collect the information.
SOLUTION:
Waiting for a fix in a future version of Toad for Oracle.