Chances are that for some reason it needs a tty and once the terminal's gone, it thrashes around looking for one, pegging the CPU in the process. Not exactly the most robust application. If it's open source, submit a bug or fix it. If it's commercial, yell at your vendor.

You wouldn't believe the effot I had to go to to get Sybase's EAServer application server to run under Solaris as a daemon. What they want you to do is log into a X session and run the application, which spawns a new xterm and keeps its "console" there, even though it's output only. They were uninterested in fixing the problem.