CorelDRAW Graphics Suite 12 :: Take White Background Out Of Scanned Logo?

I'm creating two websites for two different clients, and both gave me scanned copies of their logos.  I converted them to GIF, JPG, BMP and PNG (from MS paint program), followed all the directions found online in various combinations to remove the white background from these logos.  Here's a sample of what I did:

import logo; edit bitmap; change background; used magic wand on white areas; close paint & export doc.  I've tried various combinations of clicking on options like transparency, masking, changing the tolerance and nothing works.

On one the white background simply won't go away after saving to my desktop, and on the other there is a grey/white checkerboard pattern on the background.

When it's all said & done, I need to upload these to Wix.com as a PNG.

I'm at my wits end been trying to do this for two days after work, wondering if Corel is even capable of doing this, or if my clients' logos are just unusable or if I'm just losing it.