The problem seems to be because of missing 24x24 Tangerine's directory in Karmic (/usr/share/icons/tangerine/24x24). Copying the directory from Ubuntu 9.04 solved the problem for me. See also https://bugs.launchpad.net/ubuntu/+source/tangerine-icon-theme/+bug/435988 , I believe this is the same bug.
The problem seems to be because of missing 24x24 Tangerine's directory in Karmic (/usr/share/ icons/tangerine /24x24) . Copying the directory from Ubuntu 9.04 solved the problem for me. See also https:/ /bugs.launchpad .net/ubuntu/ +source/ tangerine- icon-theme/ +bug/435988 , I believe this is the same bug.