Scripts calling scripts calling scripts problem

This may be going overboard but I have a situation during boot up of a
QNX4.24 patch E system.
As simple as I can make it here is the supposed sequence of event for the

sinit in .boot starts /etc/config/sysinit.1

sysinit.1 starts a script called /etc/config/check_install, this script
starts with a #!/bin/sh

check_install looks for a script /tmp/install.script, if found
starts it, this script also starts with #!/bin/sh

install.script looks for and starts the script
/tmp/errata.script, which starts with #!/bin/sh.

errata.script exits

install.script exits

check_install exits

sysinit.1 then calls ph to start Photon

Now some times sysinit.1 does not start Photon. The console contains the
lines executed by the
previous scripts and if I press the Enter key I get a ‘#’ prompt. I am
working on determining in
what scripts shell I am still in, but is there some reason why a scripts
shell would not terminate?

Ivan Bannon
RJG Inc.