I am looking into this and will get back to you when I have more information.
Thank you Genevieve and thank you Genevieve.
I discovered formscentral in November last year and I knew immediately
that I could make a video competition out of it!
can you email me (firstname.lastname@example.org) the original PDF (before you imported it in FormsCentral)? Also, I'm curious about the format of the video in the PDF. Does the video in the PDF worked in Linux/Unix before going through the FormsCentral import/export?
When I look at your PDF on my Red Hat Entrprise Linux 6.0 system with Reader 9.5.4 it does look fine (location of the fields) but the video generate an error (which I'm still investigating). I have not yet try the submit button on your form (as I don't want to submit bad data to you) but I seem to have an issue with the submit button on other PDF forms I generated (when I try to submit from a linux machine). Still investigating that as well.
The fact that people can't submit from linux could be one or two reasons :
1) Adobe is not really supporting Reader on Linux/Unix anymore (officially later this year I think) so there might be an actual Linux/Unix bug in Reader
2) There was an issue with the latest update (in January 2013) of Reader which may have broken submissions (not specific to Linux/Unix).
I would suggest that you tell your fillers to use the free Adobe Reader or Adobe Acrobat on a windows or mac machine or even use the Adobe Reader on their mobile device to fill out your form.
I am sorry that I couldn't really help you more than this but since the support for Reader on linux is being dropped don't think this will get fixed.