Certain directory hits not recorded in access log

We are running Apache 2 on Red Hat 9 and are having an interesting
problem.

Hits to the pages and graphics in one particular subdirectory are not
being reflected in the access_log file, although we know from
communicating with people who have visited that the pages are being
viewed.

Is there a setting in a config file or something that would prevent a
directory from being logged?

This is a legacy system that we inherited and are not certain whether
someone might have done this previously.

Thanks,

Steve