500 Internal Server Error & On Load Attachments

Hi all!

I hope someone could point me in a direction for figuring out this error:

500 Internal Server Error: The server encountered an internal error or
misconfiguration and was unable to complete your request.

Please contact the server administrator, mcalado@tbstaxservices.com and
inform them of the time the error occurred, and anything you might have done
that may have caused the error. More information about this error may be
available in the server error log.

This occurs when trying to add a doc/jpeg/xls/etc. to a ticket when the
loaded file is larger than 1Mb.

I have already checked the:

PHP

[root@myserver]# cat /etc/php.ini | grep upload_max

upload_max_filesize = 8M

MYSQL

[root@myserver]# cat /etc/my.cnf | grep max-allowed

max-allowed-packet = 16M

RT

[root@myserver]# cat /opt/rt4/etc/RT_Config.pm | grep MaxAttachmentSize

Set($MaxAttachmentSize, 10_000_000); # 10M

No error on logs: messages, access_log, error_log

When I choose a file up to 1M and click on “Ädd More Files” …. go ahead….but
if the loaded file is larger than 1mb……if sum of (File1+ File2 + File3) =>
1Mb ….show an error!

Any idea?

Thank you!

Marcelo Calado.