Problems decoding files

[iks]

Hey everyone,
I've been trying to decode some site I got but ran into troubles.
I downloaded and tested with every decode I could find up to a point that I even tried malware infected files in hope of getting it.

I am having 2 problems that any help with would be dearly appreciated.
The first:
Most versions I downloaded are incompatible (Fatal error: Incompatible file format: The encoded file has format major ID 65540, whereas the Optimizer expects 2 ). Assuming I only have the files how can I identify which version should be used?

My second issue, I was able with iDezender 8.1 (from leakforums) to decode most of the files, but some of them are still a little messed up like this:
function index()
{
$í´'±Òº~8ûnš ŠÉÏþ = &$GLOBALS["__rootadminNoHTML"];
$í´'±Òº~8ûnš ŠÉÏþ = false;
$¦éY = &$GLOBALS["_UI"];
$Æ»ükl<Þù = UcPhotoComments::find_all();
$¦éY->assign("comments", $Æ»ükl<Þù);
return "rootadmin/uc_photo_comments/index.tpl";
}

attached is a sample file.

I am not looking for someone to decrypt my files, but rather educate me as to what my problems are and recommend on what should I do?