I have a CSS file that looks fine when I open it using gedit, but when it\'s read by PHP (to merge all the CSS files into one), this CSS has the following characters prepend
I had the same problem. The problem was because one of my php files was in utf-8 (the most important, the configuaration file which is included in all php files).
In my case, I had 2 different solutions which worked for me :
First, I changed the Apache Configuration by using AddDefaultCharsetDirective in configuration files (or in .htaccess). This solution forces Apache to use the correct encodage.
AddDefaultCharset ISO-8859-1
The second solution was to change the bad encoding of the php file.