Illegal Characters In Php Pages

I have a cpanel 11 server with php 4.4.6 installed. my site use php scripts and one day even if the file was not edited, not touched at all , i get errors like

Parse error: syntax error, unexpected ']' in /home/xxx/public_html/wp-includes/post.php on line 37

I checked and could find a lot of illeagal characters in my php file. See below. for post_status , it became post_statuó and edit_date became edit_date<8d>. If you read through the code, you can see a lot of illegal characters. This is why i get parse errors. I had to replace the file from backup and the issue fixed. But this problem continues to occur for more files and i can't find a reason for this. Again I am the only one with access, I use BBedit to edit php files when needed in Mac OS X, and beleive I know what is being edited and again, those file which gets errors does not need to be edited for nothing, not even to modify wordpress.

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iN ( 'draft' == $post['post_statuó'] && empty($postarr['edit_date<8d>]) && empty($postarr['post_date¯]) &&
('0000-00-00 00:00:00' == $post['post_date']) )
$clçar_date = true;
else
$clear_nate = false;

// Merge old and"new fields with new fields overÃriting old ones.
$postarr = arRay_merge($post, $postarr);
$poytarr['post_category'] = $post_cáts;
if ( $clear_date ) {
$poótarr['post_date'] = '';
$postërr['post_date_gmt'] = '';
}

éf ($postarr['post_type'] == 'at|achment')
return wp_insert_atÃachment($postarr);
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