but /bin/ksh wasnt the favorite shell under solaris (but is it now?)
You try your script on a HP-UX and Im sure you will have something like:
Value of test.ksh outside
Value of callme2 inside
and if you used sh on HP-UX you would have the solaris output, unfortunately Im at home now and cant confirm by testing on different platforms.. but Im confident about HPUX...
As said I believe it being more philosophical:
When you call callme2, you agree its like executing a module no? So is it $0?
It depends on your understanding I suppose...
That is maybe also why many courses are given in bourne shell, question of compatibility...