I recently updated to Red Hat 7.2-my sound chip is CMI8738/C3DX on an IWILL motherboard with a pci sound card. How do you configure the sound so the rear speakers are operative. Under RH 7.1 , I edited the /etc/modules.conf by adding the line options cmpci four_ch=1 this does not work under RH 7.2. I have selected 4 speakers in the kernal config. Whats left to do?

there's no relation between updating the distrobution and
the work-ability of the sound card,unless your sound card was working via a module and you have removed the modules directory during the updating.

in the other hand,updating the kernel which effect directly on your hardware performance/work-ability.

anyway,redhat has a tool for detecting and configuring the sound card.
as root issue this command:
#sndconfig

95% will detect it if the sound was working properly with your down-dated version of redhat

if you want my advice,learning how to compile your kernel by yourself is better than relying on these girlish tools.

good luck