These are a list of files (below that were moded when you installed this mod.
download the mod again to your computer then go to this website listed below
use this mod parser (by uploading it to here
http://resourcez.biz/PackageParser/ ) pick the ver 1.1.11 or what ever ver your using and choose install and let it load the page. follow the directions
use a file editor like EditPluse3 and edit the files that have
duplicates.... not all the files below will need to be changed, not sure of the ones off the top of my head but I had the same issues your haveing. and i just fixed mine.
./index.php
./Sources/Subs.php
./Themes/default/index.template.php
./Themes/default/BoardIndex.template.php
./Themes/default/Display.template.php
./Themes/default/MessageIndex.template.php
./Sources/ManagePermissions.php
./Sources/Ads.php
./Sources/LoadAds.php
./Themes/default/Ads.template.php
./Themes/default/languages/Ads.english.php