Limitations in WordPress?

Hello, I am new to WordPress. I created the site coalriverwind.org and on that site, we have a petition that people sign. It seems that when I try and pass more than 3 fields worth of data from a form on a wordpress page to another wordpress page, or pass data in the address, I get a “Sorry, no posts matched your criteria.” error.

I was wondering if there are any limitations in wordpress that limit how much data is passed from page to page and how it is passed?

Thanks,

Matt Noerpel