$sth_imei = $dbh->prepare_cached(<<__EOSQL__); 
SELECT imei 
FROM imei_period 
WHERE (mobile_number = ?) AND 
      (account_no = ?)
__EOSQL__

	$sth_acc = $dbh->prepare_cached(<<__EOSQL__);
SELECT customer.password, 
       to_char(max(ar_open.bill_date),'DD.MM.YYYY') 
FROM customer, ar_open 
WHERE (customer.account_no = ar_open.account_no) AND 
      (customer.account_no = ?) 
GROUP BY customer.password,
         to_char(sysdate,'DD.MM.YYYY'), 
         to_char(sysdate,'HH24:MI:SS')
__EOSQL__

# [..]

$sth_imei->execute($rec[1],$rec[0]);
@imei = $sth_imei->fetchrow_array;
print "IMEI : @imei\n";
# This does not return anything )o;

$sth_acc->execute($rec[0]);
@acc = $sth_acc->fetchrow_array;
print "ACC : @acc\n";    
# This one works fine