my application

Hello,
sorry, if this question must be in another group.

I use Visual C++ and driver, connect to PostgeSQL.
Application works fine, but some time I have problem.
My application read data from another SQL server and tranfers to
PostgreSQL server. But sometime, my client hangs up, when it makes
new inset to PostgreSQL.
Maybe I over fill server buffer and I must clear it?
After each 100 insert I make PQreset(m_conn);
But this don't help and sometime, when I use this:

if (!m_res || PQresultStatus(m_res) != PGRES_COMMAND_OK)
{
wevent(strSQL);
PQclear(m_res);
m_res = PQexec(m_conn, "ABORT") ;
PQclear(m_res);
return 17;
}
application gets hangs up.
I don't get error and it don't return 17. My program stay and do nothing.
If I try insert this record with pgamin, it will also hangs up.
If I reboot postgreSQL server, it will works fine and I can run my
application
and it can insert this record and go.
Thanks for answers.
Dz.