I tried the ktrace, and here's what I get...

   380 ktrace   RET   ktrace 0
   380 ktrace   CALL  execve(0xf7bfda77,0xf7bfd9b8,0xf7bfd9c0)
   380 ktrace   NAMI  "./tsetup"
   380 tsetup   EMUL  "svr4"
   380 tsetup   RET   execve 0
   380 tsetup   CALL  setegid(0xf7bfd990)
   380 tsetup   RET   setegid 0
   380 tsetup   CALL  #45 (unimplemented plock)
   380 tsetup   PSIG  SIGSYS SIG_DFL
   380 tsetup   NAMI  "tsetup.core"

And the other program gives similar results.  This is with the new compat
code, as of Jan 6th.  (I just grabbed system.tar.gz and compiled with
that.)  Here's the other result:

   396 ktrace   RET   ktrace 0
   396 ktrace   CALL  execve(0xf7bfda77,0xf7bfd9b0,0xf7bfd9b8)
   396 ktrace   NAMI  "./xsetup"
   396 xsetup   EMUL  "svr4"
   396 xsetup   RET   execve 0
   396 xsetup   CALL  setegid(0xf7bfd990)
   396 xsetup   RET   setegid 0
   396 xsetup   CALL  #45 (unimplemented plock)
   396 xsetup   PSIG  SIGSYS SIG_DFL
   396 xsetup   NAMI  "xsetup.core"

I dunno!  I am going to try to look at the linux compat code, and see if I
can figure out what is wrong...  Thank you to all who replied.  I used a
little of everyone's advice.  :)

Mark