Check the file /etc/inittab. You should have an entry like T1:xx:respawn:command. The command is that causing the problem. Also take a look at the inittab man page:
The process will be restarted whenever it terminates (e.g. getty).
and at the init man:
If init finds that it is continuously respawning an entry more than 10 times in 2 minutes, it
will assume that there is an error in the command string, generate an error message on the
system console, and refuse to respawn this entry until either 5 minutes has elapsed or it
receives a signal. This prevents it from eating up system resources when someone makes a
typographical error in the /etc/inittab file or the program for the entry is removed.