BD Root check

Hello!
I have a problem with an insert statement in MaxDB version 7.5.0.19.

The insert is as follow:

INSERT INTO HUMAN_RESOURCE_PROFILE
(
E_HUM_RES_K_HUMAN_RESOURCE,
N_ICON,
N_SIGNATURE,
N_LOGO,
N_CURRICULUM,
N_GENERIC_INFO,
F_AGREEMENT,
K_PROG,
D_START,
O_MODIFY,
E_OPERATOR_K_OPERATOR
) VALUES (
TO_NUMBER('300078'),
null,
null,
null,
null,
null,
'T',
(select NVL(MAX(K_PROG)+1,1) FROM HUMAN_RESOURCE_PROFILE WHERE
E_HUM_RES_K_HUMAN_RESOURCE=300078),
TRUNC(SYSDATE),
SYSDATE,
'guest'
)

I receive the message using jdbc connection:

4960003 - 22/11/2004 13:02:40 003 - error - SqlMgr - PoolThread-9 -
executeBatchList: exception [-602]: System error: BD Root check
   ANSI-92 SQL State:S0602
   Vendor Error code:-602

Using SqlStudio everything goes fine.

Why this difference between Jdbc and SqlStudio?

Deleting the subquery 
select NVL(MAX(K_PROG)+1,1) FROM HUMAN_RESOURCE_PROFILE WHERE
E_HUM_RES_K_HUMAN_RESOURCE=300078
resolves the problem.
An option could be to change the insert in the following way:

INSERT INTO HUMAN_RESOURCE_PROFILE
(
E_HUM_RES_K_HUMAN_RESOURCE,
N_ICON,
N_SIGNATURE,
N_LOGO,
N_CURRICULUM,
N_GENERIC_INFO,
F_AGREEMENT,
K_PROG,
D_START,
O_MODIFY,
E_OPERATOR_K_OPERATOR
) 
select TO_NUMBER('300078'),
null,
null,
null,
null,
null,
'T',
b.c,
TRUNC(SYSDATE),
SYSDATE,
'guest'
from dual a
cross join 
(select NVL(MAX(K_PROG)+1,1) c FROM HUMAN_RESOURCE_PROFILE WHERE
E_HUM_RES_K_HUMAN_RESOURCE=300078) b

But because the field N_CURRICULUM is a long ascii field, I couldn't do that 
because you can't act an insert on long field using the insert to.... 
select.... form.

Have you some hint?

Thanks,
   Matteo