Gnome-PackageKit on Fedora 10 x86-64
After hiding a task window (e.g., downloading, checking dependencies, etc), and then reopening it from the tray icon, the icon on the left side appears as a yellow triangle with a "!" in it.
To recreate: Open PackageKit and perform any task. Hide the window by clicking the "Close" button. Open the window from the tray icon.
Filed as Red Hat bug 471595
This bug report is very old and based on a version not supported anymore. By upgrading to a newer version of PackageKit you could receive bug fixes and new functionality. You may need to upgrade your Linux distribution to obtain a newer version of PackageKit.
Please feel free to reopen this bug if the problem still occurs with the latest version.