Pls Help: Moving script from Win to Linux

Greetings gang. You know me, I never ask for help if I haven't checked all my other options, but this is day two, and I'm getting spanked on this one. Some recently moved scripts from a WIN2K server running PHP 4.2.1 to an Apache PHP 4.2.3 setup have stop accepting HTML Form Variables. I can pass variables till I am blue in the face, even see them in the URL but they are still showing up as (!isset) My ISP (Whom is using Virtual Directories) has no solution, and I have tried every code variation I could think of to troubleshoot it. This code has been working fine for Months on the WIN2K box, but just doesn't pass a var on the Linux solution. Can any Server pros out there possibly throw me a bone? My deadline is looming. :^) As always, a million thanks in advance. Yours truly. -NorthBayShane