With some customizing, l have everything with a brushed style look, like Safari. I have my contact list this way as well, with a picture of the brush in the background. I have my contact style as 'borderless window'.
But when l want to see the contacts as 'groups bubbles' or 'contact bubbles', the background goes away, despite the option still being checked.
Not a big deal to me, but you might want to investigate it.
The background picture only works with the Regular and borderless window styles. That's just how it's been. It's kinda hard for Adium to break up the image for group and contact bubbles.
