With CSS Menus enabled (PHP Layers disabled), text and images on the background page show through the menu. See attachment image.
I can reproduce this on tw.o, as well as www.cbbca.ca (coelesce theme) but only using IE7 (I have reports it's broken in IE7 as well).
I looked for a z-index setting that was wrong, but couldn't find any. It may be a background transparency problem.
To help developers solve the bug, we kindly request that you demonstrate your bug on a show2.tiki.org instance. To start, simply select a version and click on "Create show2.tiki.org instance". Once the instance is ready (in a minute or two), as indicated in the status window below, you can then access that instance, login (the initial admin username/password is "admin") and configure the Tiki to demonstrate your bug. Priority will be given to bugs that have been demonstrated on show2.tiki.org.
Unable to connect to show.tikiwiki.org. Please let us know of the problem so that we can do something about it. Thanks.