This have been the most annoying problem for me. I’m using Snow Leopard 10.6, but according to bug reports, it exists since Tiger 10.4.
If you have a nice GDI printer Xerox Phaser 3117, you will wonder there’s no driver for Mac OS X and Xerox website says this printer is not supported in Mac OS X 10.6.
As you know Mac OS X uses Apple’s developed CUPS (Common UNIX Printing System), so I’ve been used this printer on FreeBSD with Samsung GDI driver, but that wasn’t working via Mac’s interface. Even though there’s a special drivers build for this printer Splix, that was not working properly.
Sometimes I needed several windows of FileZilla on my Mac to work with several servers simultaneously, but it doesn’t support multiple sessions (yet?). And Mac OS X doesn’t allow to launch another copy of application, so I googled a bit to find a solution… So you can run it by launching another instance of the app by typing this to command line: