libpqxx + postgresql connection

Hi all,
I am using libpqxx to connct to Pgsql database. Following is
my code in a connect method of a class

try
{
conninfo = "host=127.0.0.1 dbname = DatabaseName user=uname";
conn = new connection(conninfo);

}
catch (const sql_error &roSqlQueryError)
{
printf("In Error \n");
string szQueryError = roSqlQueryError.what();
szQueryError += "Query was:: ";
szQueryError += roSqlQueryError.query();
throw runtime_error(szQueryError);
}

But when i use this connection in later stage it results to segmentation
fault.

I changed database name to wrong dbname (non existing database) then also it
doesnt go to catch staatement...

Can ny body tell me what is teh problem with this????