Getting error "ORA-01438: value larger than specified precision allowed for this column" when trying to "Copy data to another schema" to an identical table (4333303)

This problem also happens when trying to export dataset and is related to scientific notation.
Steps to reproduce the issue:

1. Run script below:

create table testScientific (
col1  NUMBER(20)
);

insert into testScientific values (99999999999999999999);

commit;

select * from testScientific;

2. The grid displays:

1.0000E+20

3. Now select the table in the schema browser., go to the data tab , r-click and select "Export Dataset" as insert statements.

The insert generated is :

Insert into TESTSCIENTIFIC
   (COL1)
 Values
   (1E20);
COMMIT;

If you run it you get the error:

ORA-01438: value larger than specified precision allowed for this column

WORKAROUND

Go to View | Toad Options | Data Grids | Data |  and uncheck "Display large numbers in Scientific notation"

STATUS

Waiting for fix in a future release of Toad for Oracle