Seems like you may just be missing a step with those photos using corel...Never fear, though! There are 2 options that you can use, one is "easy" and one is more technical (using corel-draw)... both sets of tools are useful, and can be used in combination as well.
1. Easy Method:
Download the Microsoft Image Resizer, which is one of the PowerToys for Windows XP. While you're there poke around a bit, they have some nifty little computer tools there - you may have another "ah-hah!" moment.
The image resizer integrates into the context menu, so when you right click on pictures in windows explorer you have an option to resize images. When you click on that, a menu pops up, but it's pretty self explanatory. Resizing to 640x480 typically yields an image file size under the 80kb limit with no noticeable artifacting or jaggies.
You may want to pre-crop the photos to be resized using the image editing software of your choice, rather than just resizing the original image directly off of the camera.
2. Technical Method (Corel Photopaint 8, your version of Corel may vary but the concepts are typically similar across all editing software):
a. Create a copy of your original photo and rename it. This way if you mess up somehow you will always have the original. I typically just add "edited" to the file name of the second image at this point, although you could copy and paste the images to be edited into a folder of their own instead.
b. Open the copy of your picture in Corel Photopaint, Crop, adjust levels and otherwise manipulate the image to suit.
c. On the top menu bar, under the "image" heading, choose "resample" and set the largest value (length or width) to 640 pixels (change the unit to pixels if necessary) if necessary (your camera may take the pictures at the correct resolution already although it's time for a new camera if so
), making sure that "maintain aspect ratio" is checked. If the photo is to be used for the web, be sure to set the dpi or resolution value to 72 dpi (if it isn't already), as this drastically affects file size.
d. Save your picture - at this point you will be given options for compression. I find that 20-30% compression has very little effect on the final product for web applications. Use the lowest amount of compression which will yield a file size under 80k. The dialogue box should inform you of your finished product size, although there may be a button you need to push (in Corel Photopaint 8 you need to hit "preview" for it to recalculate the file size).
e. Check your photo file size in windows explorer, and preview it in the windows picture and fax viewer (default windows picture interface under XP, available in the context menu under "open with" if the default has been changed by certain control-freak software packages). If the file size is too big, you may need to add more compression, crop more, etc. You may want to start over, as well (you did save your original right?) depending on how your final product looks.