Webpage Persistence Load balancing

I'm having a webpage Persistence problem, it is intermittent.  I suspect it is caused by load-balancing.

Specifically:

Users are connected to a webpage form to complete.  Generally, everything is OK if they take a minute or even more to 
complete the form. However, sometimes they report to me, and I've seen it myself, the connection has been dropped by the 
server in a short time.  They enter the data and Submit it to the server, and the page just reloads and their data is 
lost.

I have the PHP ignore_user_abort(true); etc.

Is there anything I can do to fix this or is it a server issue that you must fix?

Thanks, Al.........