PsotgreSQL 8.4 crach on C-language function

Hello,

I am experimenting with user defined functions in C, though I have
problem with stability.

It always crach on palloc() call, SPI_tuptable->tupdesc dereference
but not on SPI_* calls, for example.

Here is one modified example:

PGDLLIMPORT Datum test(PG_FUNCTION_ARGS)
{
char *command;
int ret;
int proc;

command = "SELECT 1";

elog(INFO,"1");

SPI_connect();

elog(INFO,"2");

ret = SPI_exec(command, 1);

elog(INFO,"3");

proc = SPI_processed;

elog(INFO,"4");
/*
* If some rows were fetched, print them via elog(INFO).
*/
if (ret > 0 && SPI_tuptable != NULL)
{
TupleDesc tupdesc = SPI_tuptable->tupdesc;
SPITupleTable *tuptable = SPI_tuptable;
char buf[8192];
int i, j;

elog(INFO,"5");
for (j = 0; j < proc; j++)
{
HeapTuple tuple = tuptable->vals[j];

elog(INFO,"6");
for (i = 1, buf[0] = 0; i <= tupdesc->natts; i++)
{
snprintf(buf + strlen (buf), sizeof(buf) - strlen(buf), " %s%s",
SPI_getvalue(tuple, tupdesc, i),
(i == tupdesc->natts) ? " " : " |");

elog(INFO,"7");
}
elog(INFO, "EXECQ: %s", buf);
}
}

SPI_finish();
pfree(command);

}

"elog(INFO,"5");" line is not executed, I have to restart crashed
server after error:

LOG: server process (PID 1628) was terminated by exception 0xC0000005
HINT: See C include file "ntstatus.h" for a description of the
hexadecimal value.
LOG: terminating any other active server processes

0xC0000005 is access violation, but I can't follow why.

I am using Visual Studio 2005 SP1 compiler. Since mine PostgreSQL 8.4
server uses msvcr71.dll, not 80, maybe it's compiler incompatibility
of some kind?