Overriding log_error in Rails3 not working

I have this in my application.rb:
private
def log_error(exception)
super
UserMailer.error_message(exception,
clean_backtrace(exception),
session.instance_variable_get("@data"),
params,
request.env
).deliver
end

I’d like the errors emailed to me.

It doesn’t seem to be calling that “log_error” at all.

Is this done some other way in Rails3?