PDF Fusion - setting custom paper sizes

How are custom paper sizes (24"x36", 18"x24" and other sizes) set in PDF Fusion.? The operating system is Windows XP Pro. I have tried going to Start,  Settings, Printers and Faxes then highlight Corel PDF Creator, then click on File and go down to server properties. The dialogue box pops up and under the Forms tab is an area to set custom sizes. I created a 24"x36" sheet size and saved it. Then went to AutoCad 2004 and opened a drawing and tried to make a PDF of it. The 24"x36" option showed up in select paper size box which I selected. I windowed the drawing and did a preview of the plot, which showed correctly on the 24"x36" sheet. I clicked ok and the job did print after a short delay. I then opened the PDF and the result was that it came out on an 8-1/2" x11" format. I tried several times. Some help would be greatly appreciated.

I tried re-booting after making the change to no avail.