since you checked the necessary things you needed to check to verify why your system isn't scheduling the jobs at the desired time, i say you try scheduling the job another method.

It's been a while since I've done this but from what I remember, i know you can schedule at job times anyway you want.

for instance, you scheduled your at jobs like this:

at 06:50 02/02/03 /orac/ora11/temp/sun_job1.sh

try replacing the "06:50" with something else equivalent. I think you can replace it with words but am not sure. anyway, what am saying is, change the syntax of these current jobs so the new syntax is different but equivalent