When upgrading my Mac from Tiger to Leopard, I had to remove the Logitech Control Center software. It relied on the Application Enhancer (APE) and caused the famous blue-screen-after-installation. Leopards’ systems settings provide some basic functionality for correctly binding keys from a Windows keyboard, but I really missed some of LCC’s features (e.g. binding the middle mouse button in a UNIX-style way to the “paste” keyboard shortcut).
Logitech has since updated LCC to version 2.4.0 but unfortunately they didn’t get it completely right this time (again). The software seems to work fine on Leopard (you can bind your keys to whatever action you want and see the battery status of your wireless keyboard and mouse), but it breaks Growl’s display notification.
So far, removing the folder
/Library/InputManagers/LCC Scroll Enhancer Loader (and a reboot) results in Growl working properly again and the key bindings still work, too. If anyone experiences problems with this solution, please post them in the comments.
(Thanks to the folks at the Growl forum for their help with this issue)