Emacs-AUCTeX-Okular
Solution 1:
I came across the same problem today on Ubuntu 12.04. The main problem is that the Emacs window is not brought to front.
I am using Ubuntu 12.04 with Emacs/AucTex/Okular/TexLive 2011. I found that if I press Shift+LeftMouse twice in Okular, the Emacs window will be brought front. So this can be seen as a workaround.
You could also configure the Custom Text-Editor in Okular.
First install xdotool
sudo apt-get install xdotool
Then save the following script
#!/bin/bash
emacsclient -a emacs --no-wait +$1 $2
fs=$2
filename=$(basename "$fs")
pathname=$(dirname "$fs")
xdotool search --name $filename windowactivate
The script will first call emacsclient, then bring a window whose title contains the filename of the TeX source to front.
Make the script executable and write the following command (don't include ~ in your path) in the Custom Text-Editor in Okular.
<absolute-path-to-script> %l %f
Hope it works.