I've poked around quite a bit looking for the option to change/remove this, but I cannot seem to find it. It is far too obtrusive for my tastes and i would dearly love to remove it, if possible -- or make it 1px if it is not possible to remove it.

Any help you can offer would be greatly appreciated. Thank you!

This is almost certainly not done by AdiBags (the addon doesn't touch tooltips in any way as far as I know). Try to disable your addons individually to see which one is to blame. My guess would be an outdated theming engine that is missing border textures.

Interesting. It didn't happen until i installed AdiBags this morning, but I'll take a peek at my tooltip addon.

Thanks for responding!