For the record: None of our applications are designed for, tested on, or validated to work with PHP 5.3.x at all.
PHP 5.3 depreciates certain functions that I know we use, as well as introducing new features which I know conflict at the moment with our code.
As soon as I get a chance I will refactor those parts of the code effected and re-release new versions.
Out products are designed for PHP 5.2.x (5.2.4 and above) which, in our experience, is the version most webhosts have installed as its the only major version of PHP that ships with the mainstream linux distributions (redhat/centos).
Update (7th Jan 2010):I have now succeeded in getting bfForms and bfFramework to function correctly on PHP 5.3.x, there were significant changes that had to be made – this was made a lot easier as the codebase is Unit tested. I’ll release a copy soon, as soon as its been to our testers and passed their approval. I’ll make a further announcement when this has been released.