same here, no form works with update1
I am now back to the original version 12 and all forms on all imported and new sites work
I am using layout is a form and publish method is 4.01 with tables
I can enter the action path, then as soon as I publish, the action path in the resulting html is replaced with FormHandler.php, even the property palette reverts to FormHandler.php and the path I typed is gone
using Win7 64bit ultimate with all updates
I also tried it on my XP and it does the same, so it is not an OS issue