Note: This document is getting a bit old and may not be 100% accurate anymore but is still worth a look if you are having any of these problems.
Clear your cache! I've had countless "bug reports" taken care of simply by telling people to clear their cache. Cache can cause all sorts of weirdness. This should be the first thing you do followed by a hard browser refresh.
Problem: CSS/template overrides are not working in non default themes.
Solution: There is an issue with the global $theme variable not being set affecting only some sites that has never been solved. To work around this, I fall back to the default theme when the variable isn't set. For sites with this problem, you need to put your AF theme overrides in your default theme.
Problem: Fatal error: Unsupported operand types in /path/sites/all/modules/advanced_forum/includes/style.inc on line 132 (that number may change)
Solution: This error occurs when your site's theme is not enabled. Go to admin/build/themes and enable it.
Problem: Bullets missing in Artisteer themes.
Problem: The views count is not showing up on the topic list.