Well is clear that if you want to use the amazon elb, you will not see the $REMOTE_ADDR correctly and you will need mor_rpaf enabled and installed.
If you have a centos / redhat server I found this nice tutorial on this page
mod_rpaf and Amazon ELB
mod_rpaf-0.6-0.7.x86_64.rpm
And add this
LoadModule rpaf_module modules/mod_rpaf-2.0.so
RPAFenable On
RPAFsethostname On
RPAFproxy_ips 10.
RPAFheader X-Forwarded-For