The error is being thrown on loading the map; approximately 80-90% of the time.
Also of interest may be the following gunk from the error logs:
[Wed Jul 12 16:29:11 2006] [error] [client x] Premature end of script headers: php-cgi.exe, referer: http://x/lbia_dev/
[Wed Jul 12 16:51:08 2006] [error] [client x] Premature end of script headers: php-cgi.exe, referer: http://x/lbia_dev/
(etc)
The error you are seeing might have to do more with apache and the long delay when getting data.
This might be the doc you should be looking at:
HTH
Ludwig
