Hi Nick Messina:
Thanks for posting.
What version of FileMaker are you hosting from?
What operating system is the host running on?
What image format are your images using?
The first thing you can check is how the image is displayed directly in a web browser. Open one of your browsers and use the open file option to test what comes up for the actual image. You can also modify the images so the backgrounds match the background color in your layout. This way the border should blend in for Instant Web Publishing. If you are trying to use transparency in the image, you need to use the GIF format for your images. The GIF format is supported in FileMaker for showing transparency.