Embedded C SQL Error -600

Using PostgreSQL 7.3.1 on a customized Linux slackware host 8.0.0
I am receiving an error -600 from this bit of code:

EXEC SQL FETCH FROM test_cursor
INTO :mach_seq, :ss_mseq, :child_idx, :job, :net_pieces, :start_time;
printf ("b4 while test_cursor_select SQLCODE %d\n", SQLCODE);
while (SQLCODE != ECPG_NOT_FOUND)
// while (!SQLCODE)
{
EXEC SQL FETCH FROM test_cursor
INTO :mach_seq, :ss_mseq, :child_idx, :job, :net_pieces, :start_time;
EXEC SQL FETCH FROM test_cursor
INTO :mach_seq, :ss_mseq, :child_idx, :job, :net_pieces, :start_time;
}

in ecpgerrno.h this entry:
/* backend WARNINGs, starting at 600 */
#define ECPG_WARNING_UNRECOGNIZED -600
/* WARNING: (transaction aborted): queries ignored until END */
implies that a transaction with this code would be aborted, as well as not
being too informative about the nature of the problem.

The commented line '// while (!SQLCODE)' fits the style of existing code
better.

I get the output I would expect if there were no problem:
b4 while test_cursor_select SQLCODE -600
i 0 machseq 73374, ssmseq 3404562 child 0 job 410F 3 , net
pieces 0, start_time 2003-02-10 11:00:00
i 0 machseq 73374, ssmseq 3404562 child 1 job 410F 3 , net
pieces 254, start_time 2003-02-10 11:00:00
i 0 machseq 73374, ssmseq 3404562 child 2 job 410F 3 , net
pieces 508, start_time 2003-02-10 11:00:00
i 0 machseq 73374, ssmseq 3404562 child 3 job 410F 3 , net
pieces 762, start_time 2003-02-10 11:00:00

Is this an error that can be ignored? If not, what should I be looking for?

Heisenberg may have slept here