I created a generic form (using a "custom" page size - 8.27x11) and included the Interactive fillable fields. When I exported to PDF and tested the fillable form, all the fields worked and were in the order I placed /arranged them using "Tab Order".
I then choose "Alternate Layout" - specifically A4, exported to PDF again, but his time some of my fields became out of order. I went back and cheked my "custom" form (just to be sure) and it is ok.
Any help on this?
It sounds like a bug. Both of those features are new in CS6. Probably no one tested them together. You'll probably have to separate the layouts into separate documents.
You can report bugs here: