Need transparent background around bitmap graphic

I've been struggling with directions I found somewhere around CorelDRAW.com, but it's still not happening. I really need someone to walk me through this, if possible.

I have a JPG with a graphic over a white background. I converted to GIF using Corel PHOTOPAINT. In the GIF Export window, hitting the background with the eyedropper tool is supposed to make anything that color transparent. Things appeared to be working when I clicked the Preview button. But....

Whenever I try to put this new GIF on top of another bitmap, I still have the white rectangle background. I tried I converting the secondary background image to GIF, but I still have the original white box around the first image.

Help?