SQL Stored Procedure Strangeness

I have two stored procedures that I call (using RUNSQL) from two
different CL/ILE programs -- one in each. Both stored procedures have the
same header information except for the long and short names of the
procedure. I even wrote the first set and then copied then to the second
set with modifications.

When I call one with a null in the 4th parameter it accepts it
just fine. But, when I call the other, the SQL errors out saying that the
null is not accepted for that parameter and that I should specify
PARAMETER STYLE SQL -- but this is a LANGUAGE SQL stored procedure!!!

IMLFBACKUP TYPE(IMLFBACKUP) TABLE(*DTL) COMPANY(*RGN03)
CALL IM_LIFO_BACKUP ( 'IMLFBACKUP', '*DTL', '*RGN03', NULL )
...etc...

IMLFRESTOR TYPE(IMLFBACKUP) TABLE(*DTL) COMPANY(*RGN03)
Null values not allowed for parameter 4 in procedure IMLFRESTOR in *N.
RUNSQLSTM or RUNSQL command failed.

Yet, I tried adding the clause and got an error trying to build
the stored procedure -- saying that the clause was invalid!!! Help?!?
Here are the two stored procedure headers.

Create or Replace Procedure IM_LIFO_BACKUP
(
In BackupLibrary Char(10)
, In BackupTables Char(6) Default '*DTL'
, In SelectCompany Char(6)
, In RestartCompany Char(5) Default '*NONE'
)
Language SQL
Deterministic
Modifies SQL Data
Called On Null Input
Program Type MAIN
New Savepoint Level
Specific IMLFBKUSP


Create or Replace Procedure IM_LIFO_RESTORE
(
In BackupLibrary Char(10)
, In BackupTables Char(6) Default '*DTL'
, In SelectCompany Char(6)
, In RestartCompany Char(5) Default '*NONE'
)
Language SQL
Deterministic
Modifies SQL Data
Called On Null Input
Program Type MAIN
New Savepoint Level
Specific IMLFRSTSP


Sincerely,

Dave Clark