As well as the setting in php there is an apache setting
LimitRequestBody 10485760
Here is is in context in httpd.conf
### Section 1: Global Environment
#
# The directives in this section affect the overall operation of Apache,
# such as the number of concurrent requests it can handle or where it
# can find its configuration files.
#
#Added to solve file upload size problem with moodle BJL 13092004
LimitRequestBody 10485760
#
# Don't give away too much information about all the subcomponents
# we are running. Comment out this line if you don't mind remote sites
# finding out what major optional modules you are running
ServerTokens OS