Top and Bottom Widget Images With Widgets in Middle and Two Side by Side

I've followed both of these tutorials:
[SOLVED] Add top and bottom image for widget - http://forum.bytesforall.com/showthread.php?t=935
HOWTO: put an AD (or other) widget over/in the middle/under two sidebars - http://forum.bytesforall.com/showthread.php?t=5419

The second one works perfectly (http://www.in-a-dream.org/) but the first one I am still monkeying with. I'm guessing it doesn't work because of the second tutorial because the bottom two sidebars (which are the only ones I want to have top and bottom images - not the ones that span across both sidebars on top) are not named Right/Left/Inner Sidebar but instead are named "sidebar_widget_area 1" and 2.

Does anyone know how I can get my top and bottom white rounded corners to adhere to the widgets that are side by side (starting with categories and sponsors) and then have white backgrounds throughout the rest of the widget connecting them (so white rounded top on categories with a white box connecting to the rounded bottom so it looks like one rounded unit) and not on the top widgets that span across the top of the two sidebars?

It's probably too complicated. If so, I'll have to figure something else out.