intermittent error "Your config file does not appear to be formatted correctly."

[eluser]ManOfTheHour[/eluser]
Hi fellow Codeigniterers!

I have run into a curious issue I can not track down.

I get intermittent "Your config file does not appear to be formatted correctly."

Set a trap in Common.php to see what's going on, no error on *require* the config file but the $config variable
is not there. Gone. Just like that.

This issue happens *sometimes* , have not found out what sequence of page/ajax calls trigger this.
Calling the same page right after usually comes back ok.

I am running out of ideas where to look.

Using
- hooks,
- enabled get query strings,
- $config['permitted_uri_chars'] = 'a-z 0-9~%.:_\=+-';

All that has not changed before or after the problem started.

I hope you can point me a way out of this mess? Thanks!!!