The host is "FastWebHost" (formerly eHostPros), who is a little outdated, and it's an interesting point you raise that they have an aggressive list of disabled functions, but [give you the option to override them](http://support.fastwebhost.com/index.php?/Knowledgebase/Article/View/336/0/how-to-setup-a-custom-phpini-file) with a custom `php.ini` file.

So, this was how I fixed the error occurring for my site; if the developer community doesn't think that working around an `ini_set` call on `__construct()` isn't needed, I can strike that.

Regarding your reason why ini_set is needed for setting the session save handler, I think you missed a few words in your sentence. Is it a good or a bad thing that `session_set_save_handler()` sets the userland save handlers?