What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
This is our user guide on -How-to-Create-a-PDF-Form
If I am not mistaken, this is your jotform http://www.jotform.us/form/51255281705149 that you converted to Fillable PDF Form.
I checked the form and I noticed that it is indeed a very large form with multiple pages on it.
There are still some limitations to an extent the converted PDF form have. You can check for more details here
As of now, I can only suggest a re-design of your form to consider the limitations when being converted to PDF form.
Hope this help. Please let us know if there is more we can help you with.