Why entered text is not displaying on text boxes?

after entering some data on a form the textboxes become inactive.  You can select (highlight) the box as if you were going to type text but the cursor will not be highlighted in the box and no text will appear.  In order to get the textbox to work, we have had to close out of the site and re-enter. 

Is there a reason textboxes would freeze?

I have checked your last edited form http://www.jotform.us/form/71918357303155 and see that the text boxes are working fine at my end. I was able to enter the information into the form fields without any issue. Are you still experiencing any issue with the form? If so, please let us know if the form is embedded on any of your web pages or while viewing the form on any specific browser.

If you are referring to a different form, please let us know so that we can take a look and provide you necessary assistance.