only your employer can tell if you can still work for the company.
if they still needing your service then you can work again.

however, your question seems matters on the legality.
if you'd resigned from the job in NOv 2007, and your work visa expiry
still stands outstanding until today, you can come back to your same company work freely without furthermore questions from immigaration.
otherwise, upon joining once again today with visa expires on or after your
resignation date last year, your sponsor will apply you again for the
new working visa, that is subject to the immigration's verifications.