httpd denied write

[Tim Fenn <fenn stanford edu>]

I'm still a bit new to selinux, so apologies if this is a silly
question.  I've been running httpd in the past, but I've recently had
errors accessing my mythweb folder (lots of permission denied
messages) with the following logged in /var/log/messages:

Jun 11 19:11:16 agora kernel: audit(1118542276.660:0): avc:  denied  {
write } for  pid=19303 exe=/usr/sbin/httpd name=image_cache dev=sda1
ino=1392658 scontext=root:system_r:httpd_t tcontext=system_u:object_r:httpd_sys_content_t tclass=dir

this is from the php scripts in mythweb attempting to write to an
image cache, which is also under the mythweb folder.  httpd_unified is
set to 1, so I would have thought any write call by httpd would be
allowed... but I'm obviously missing something simple.  Would putting:

allow httpd_t httpd_sys_content_t:dir write;

in my policy be an appropriate solution?

Thanks for any help,
Tim F