process substitution in PROMPT_COMMAND

[Curtis Doty]

I've recently refactored my PROMPT_COMMAND function to avoid superfluous 
fork()s. In the body of the function, what was once this line:

  local jobcount=$(jobs |wc -l)

is now this:

  local job jobcount=0
  while read job
  do ((jobcount++))
  done < <(jobs)

This works fine on bash 4. However, when attempting to use this on an 
older bash 3.00.15(1) host, an error occurs; but only on 2nd or additional 
subshells--not the first login shell!?! I.e. everything works fine, until 
I run bash from bash.

  bash: foo: line 39: syntax error near unexpected token `('
  bash: foo: line 39: ` done <<(jobs);'
  bash: error importing function definition for `foo'

Am I missing a finer point of redirection from a substituted process? Or 
is something different in bash 3 that I need to work around here?

../C