I use GNOME. I want to use Amarok, but tool tips are just black boxes in Maverick. Here's what it looks like:
Is it possible to correct this by changing some settings or it is a bug? I saw this - http://ubuntuforums.org/showthread.php?p=10186430 - on the Ubuntu forums, but deleting the .kde folder did not help in my case and didn't seem to help any others either.
This is a bug: https://bugs.launchpad.net/ubuntu/+source/gtk2-engines/+bug/144968
Some KDE applications appear to change the theme settings so the tooltip is effectively black-on-black. There is a workaround (mentioned in that bug report) that involves opening the theme settings and changing the tooltip colours back, but this is temporary in that when you next launch Amarok, you'll be back at square one.
The bug suggests that this might only be a Clearlooks engine issue. Perhaps switching to another theme might help (although I realise this is far from ideal).
This problem is still present in 11.04. You can fix it by installing KDE's 'systemsettings' and setting the tooltip text color. Install using Synaptic or do 'apt-get install systemsettings'.
Run 'systemsettings' from the terminal (there is no menu item). Choose Application Appearance > Colors > Colors, and set Tooltip Text to white.