I do hope you meant something like PHP 5.3.4.5.
Anyway, spiffyCal is used with many features in ZC including some mods. Hence one of the questions in the posting tips - what mods are installed.
Have you checked the permissions on the file mentioned in post #2. It's telling you that the process is blocked. If a permission is okay, then we need to find out what's "denying the client."