The documentation and released information pertaining to PHP release is correct and accurate. It's not your PHP version that is necessarily the problem. The problem is with your host. They are using an UNPATCHED PHP release which features CRIPPLING bugs. It's possible your host also provides changing PHP release with htaccess please see
this
link for further info.
We've attempted to make internal fixes to avoid the issue (please ensure you've CB 1.2.2 installed).
Issue is also being further addressed in next release of CBSubs (1.1). If you'd like to assist in further helping resolve the issue please PM Nick for access to a beta release of 1.1 stating that I've sent you with permission to join.