Why no shebang?

I have set up PPP via The NetBSD Guide, it works, 
kinda...

But as per examples 9-7 and 9-8 I have written 
the scripts ppp-up and ppp-down.  I have also done...

chmod u+x ppp-up ppp-down

...as instructed.

But the shebang line on the first line of each...

#!/bin/sh

...seems to have no effect. So that if I type, as a user,
or as superuser, or even as root, thus...

# cd /etc/ppp
# ppp-up

...I get the nastigram COMMAND NOT FOUND from NetBSD. But
strangely enough, I can still do this...

# /bin/sh ppp-up

...and it runs just fine. I had previously noted that a
similar lack of shebang with Perl scripts. I could run
them if I called Perl, but not via shebang, regardless of
what chmod combo I'd set it with. As an experiment, I set
chmod with x at all three levels, not just "u", and also
checked up on chmod with...

# ls -l /etc/ppp

...but to no improved effect. The scripts had "x" set, 
but
still no shebang.

So my question is, "Why don't shebang? Is there something
I need to configure? Some setting somewhere?

Thanks,

Gan Starling
Kalamazoo MI USA


--

To paraphrase Hitler... "Who remembers the Amalekites?"