I finally found the solution to my issue.... and this is the procedure just in case if someone run into such problem:

1- Edit the sources list: sudo nano /etc/apt/sources.list
add the following based on your OS, mine is Debian Wheezy:::
deb http://ftp.uk.debian.org/debian wheezy-backports main
deb-src http://ftp.uk.debian.org/debian wheezy-backports main

Ctrl+X and push y to save the work.

2- update your resources: sudo apt-get update

3- install some packages that you need to the upgrade:::
sudo apt-get install dpkg-dev build-essential zlib1g-dev libpcre3 libpcre3-dev unzip

4- sudo apt-get -t wheezy-backports build-dep nginx

5- create a folder for the latest nginx packages: mkdir custom-nginx-1.4.4
go inside the dir where you created it::: cd custom-nginx-1.4.4

6- download the pkge::: sudo apt-get -t wheezy-backports source nginx

7- change the log version in the log file::: sudo nano ~/custom-nginx-1.4.4/nginx-1.4.4/debian/changelog

e.g::: originally like this 1.4.4-1~bpro70+1, then change it to anything like this 1.4.4-1~bpro70+1_sms

save your file and exit

8- enter to the main folder of nginx::: cd ~/custom-nginx-1.4.4/nginx-1.4.4
then build the pkge::: sudo dpkg-buildpackage -b

9- when the build up finished, enter these command line:::
sudo dpkg -i nginx-full_1.4.4-1~bpo70+1-sms_amd64.deb nginx-common_1.4.4-1~bpo70+1-sms_all.deb nginx_1.4.4-1~bpo70+1-sms_all.deb

10 run::: sudo apt-get -f install

and you are done. you can check the version of you nginx using this command::: nginx -v or nginx -V

These steps are based on the tut here: https://www.digitalocean.com/community/articles/how-to-add-ngx_pagespeed-module-to-nginx-in-debian-wheezy

Good luck

v.important note: in step 7, I mentioned "then change it to anything like this 1.4.4-1~bpro70+1_sms"

underscore is not allowed, so you can use hyphen instead.