succesful sale - but no message

[nippi]

I ahve a cart that sends a payment request from payments.php to a gateway.
message is received by message.php as to whether it is succesful or not, and then message displayed on result.php, and emails confriming approval of shopping compelted.

Problem is, about on in 20 times, the shop is completed succesfully, but I get no message, and no email is sent. There are no errors in my server log, but whenever it happens, they show message and result.php were not opened.

What could possibly cause this?

[Morgenhund]

1. Problems with gateway itself? Does the gateway try connecting to message.php only once?
2. Your hosting server had been overloaded? (for Unix hosting, if you have shell access, try `sarī command to get out server loads)
3. Sporadic network problems with your hosting?