[BUG?] strange PQgetisnull

Hi all,

    I got strange result with PQgetisnull, say

for empty table(I think that it's empty so null)

I guess that
after fetch some selection
PQgetisnull(result, 0, 0) should give me "1 or true"
But
it gives me
ERROR! field 0(of 0) of row 0(of 0) is not available... Segmentation
Fault

so I tried
if (PQntuples(result) == 0)
...

But  PQntules gives me "1" not "0" !

do I have to check result with
char* value = PQgetvalue(result, 0, 0);
and test value is "" or not?  any idea???

I'm using v6.3.2 on linux && Solaris.

Best Regards, C.S.Park