tbtape -s on SCO Unix 3.2.5.0

I am currently working on a upgrade for a system from Informix 4.0 to Informix 5.x. Within the crontab entry the tbtape -s is running redirecting standard input to the command to make it automated. This is working fine 80% of the time. The problem comes in when the process recieves an initial error with the tape device unable to be opened. After this the process starts to ask which level of archive to run, but instead of waiting for a response from the file it gets caught in a loop and creates a file in /tmp until the root file system fills. At this point the SCO will crash and not come back up. My question is can anyone tell me is there a better way (or any other) to make tbtape runing a level 0 archive of the system? If it errors out and aborts due to tape errors that is fine to. We just need to make this so it will not crash the entire system. Thanks in advance. Bryan