Hi,
if you want to upgrade BreezingForms from earlier versions, make sure you upgrade through the whole version stack.
You'll find all legacy releases here:
www.crosstec.de/component/docman/cat_view/3-products.html
If you just want to use the previous (non-commercial) releases you can use them as well. I suggest you always use the latest previous version then.
Regards,
Markus