Since PHP 5 came into conception there is a new security warning for developers called E_Strict. Unfortunatly this can cause quite a lot of problems for code written in the old days. The code is fine but uses techniques that are no longer used and therefore PHP throws a deprecated warning. Proplayer uses some of these techniques in their XML writer. You can turn off E_Strict by setting the following in the error_reporting line.

error_reporting = E_ALL & ~E_DEPRECATED

Once the server reads the configuration it will no longer throw any E_Strict warning.

note: You have to edit the PHP.INI file! Do not place this code in your plugin.