The work-around proposed by Siegfried De Bie doesn't entirely fix the problem, because programs that open the last-used printer instead of the user's default printer (like Adobe Reader) will still try to open the printer and hang if the missing remote printer was the one last-used.
I confirm the issue on Ubuntu 9.04, Jaunty.
The work-around proposed by Siegfried De Bie doesn't entirely fix the problem, because programs that open the last-used printer instead of the user's default printer (like Adobe Reader) will still try to open the printer and hang if the missing remote printer was the one last-used.