We have had data files well over 100K without any trouble at all so that should not be a problem. I see your email so I will examine this further. Most likely it is an issue with your hosting environment.
PHP POST should not have any limits
http://www.w3schools.com/php/php_post.asp . But it seems that sometimes server admins impose limits.
Try placing LimitRequestBody = 0 in the php.conf file
http://www.phpbuilder.com/board/showthread.php?t=10332364 . Ask you hosting provider about this and how to do this if you need help.