Out of the box, the Zend Engine is @ v2.2.0.  If you need to install a newer release of Zend Optimizer this poses a problem.  I have had nothing but trouble with Zend (miscompatabilities between releases, let alone in between them).  I was hoping that someone would know outside of the standard boilerplated excuse...guess I was wrong.

Thanks, anyway, though.  I'll stick to whatever works - no Zend'd encryption.