Engine deadlocked

We have Online Dynamic Server v7.22 on an AIX 4.1.5/IBM J40 platform. We ran into a situation yesterday where we could do very little because we were hung up waiting for a checkpoint to complete. An onmode -c also hung. We had no connections to the database but there were some archive threads still connected for some reason. No archive program was running. We broke down and called Informix as the system was unusable. They said something about the system was waiting for this archive thread to terminate but an onmode -z would not work on it. They dialed in and with out much explaination they killed (kill -9) the main oninit program. This brought the engine down and they then restarted it. This fixed our problem. My question is - Is this a valid method to bring the engine down if we run into another deadlock situation? What problems could this generate? I would like to avoid calling Informix next time. Thank you for your response.