It seems this was a compatibility issue after all. After gnome-themes-standard got updated (to the version 3.3.92) the issue is gone.
** Changed in: gtk+3.0 (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gtk+3.0 in Ubuntu. https://bugs.launchpad.net/bugs/961310 Title: black titlebars in GNOME after login Status in “gtk+3.0” package in Ubuntu: Fix Released Bug description: After logging into GNOME 3, the title bars on applications are completely black, except for a dotted outline around the close button. If I switch themes and then switch back to Adwaita, it reloads properly and everything is fine until I logout again. This just started happening this morning. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: gnome-shell 3.3.90-0ubuntu1 ProcVersionSignature: Ubuntu 3.2.0-19.30-generic 3.2.11 Uname: Linux 3.2.0-19-generic x86_64 ApportVersion: 1.94.1-0ubuntu2 Architecture: amd64 Date: Wed Mar 21 10:49:32 2012 ExecutablePath: /usr/bin/gnome-shell ProcEnviron: LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: gnome-shell UpgradeStatus: Upgraded to precise on 2012-03-19 (2 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gtk+3.0/+bug/961310/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp