Auth with PDO?

[MS47]

Hi,

sorry for my bad English...

With the package Auth and the Method ->setAuthData($key, $var) and ->getAuthData($key) i can save and get variables and objects in the $_SESSION variable.
With own created object it works fine but it does not with a PDO-object.
Here i receive an error:
Fatal error: Exception thrown without a stack frame in Unknown on line 0
Why? Or doesn't works this basically?
Many thanks ahead!

Greetings,
Markus