I can run a process in background by
$ someprog > logfile &
but if I do
$ at now < jobsfile
then nothing happens except printing
job 1 at Wed Sep 29 19:12:40 2010
P.s. you might want to check and/or clear out the queue of jobs first; otherwise it'll fire off all the test jobs you submitted at once...
What does jobsfile do? If it sends output to stdout or stdin, that will be mailed to you.