No extensions work!

Hi, could *someone* please try to help me? I've been using PHP for a while now on my Win98 machine with no problems. But I just upgraded to PHP4.06 and when installing it, I accidentally got the new install to overwrite my php.ini file. So, I had to go back into the php.ini file to add the extensions directory and enable GD extension (because I use it a lot). But, whenever I have the GD extension enabled, no PHP pages will load in. At all. No matter which server I use, it won't work. Thru Xitami won't work. Thru IIS. Thru Apache. Nothing. As soon as I disable GD, however, it all works perfectly. Except for the fact that I now don't have GD to play with. Why doesn't it work?!?! I even tried removing PHP 4.06 and reinstalling my old version 4.04! Nothing. Still when the GD extension (and any other extension) is enabled - PHP refuses to give. This has happened before to me, but it seemed to correct itself and I don't know why. Please help! Thanks! Jefferrs