Application pool restart

Hello,

i have very strange problem, last night some of our jobs started throwing exceptions on places where there are no reasons to.I have tested the jobs on my dev machine and even on test env and there the jobs are running and executing as expected.After a app pool restart on production (where the strange behavior occurred) the jobs executed normally whiteout any errors.I have experienced similar behavior a year ago when i have set the app pool to never reset on regular intervals, and after a week or so same of the jobs have been stuck in "running" state without actually doing any work.Any ideas? or direction to look?