Yes,
It seems like Apache failed at that time today:
Navigator Internet Solutions, Inc.
DOWN at Nov 18 2004 05:15 AM (GMT -4:00)
Err: invalid HTTP response (first line of response: ""
Navigator Internet Solutions, Inc.
UP at Nov 18 2004 05:20 AM (GMT -4:00)
Was down for: 05min
That's using HyperSpin monitoring service with 5 mins intervals. We will further investigate the cause.