Hi,
Not sure how it is possible to have an error in your php for the error_general.php, since it just echos the title and the message.
Have you changed it, trying to use server headers to identify the source and redirect?
Personally I would not try to avoid the error pages as this can lead to more confusion that it solves, but they are in the view files specifically so you can format them however you want.
The php error you are getting above is something you need to locate and fix.
You should never be able to submit a url to one of your functions that can cause a php error, your own error checking should take care of that.
The error pages themselves, I have never experienced them throwing an error like that, so I presume you have customized them in some way.
Sorry I cannot be of more help,
Paul.