ownership error while running an ubuntu mirror site?

[Mauricio Tavares]

So I setup an internal ubuntu mirror site using ubumirror. I setup the
cron scripts and directories to be owned by www-data since that is who
the webserver is being run as. During the last two days I have been
getting messages saying the cron jobs are not being successfully run.
So, I look at the bottom of one of the ubuarchive.log and find this:

deleting pool/universe/u/update-manager/auto-upgrade-tester_0.142.4_all.deb
deleting project/trace/atemoya.canonical.com

sent 454075 bytes  received 459730724 bytes  589602.56 bytes/sec
total size is 382786801558  speedup is 831.81
rsync error: some files/attrs were not transferred (see previous
errors) (code 23) at main.c(1526) [generator=3.0.7]
Sat, 07 Aug 2010 00:16:16 -0400: Archive pool sync failed.

I looked in the log file further up and found the following entry:

pool/main/g/glew/
pool/main/g/glib1.2/
pool/main/g/glib2.0/rsync: send_files failed to open
"/pool/main/g/glib2.0/libglib2.0-0_2.25.12-1ubuntu1_i386.deb" (in
ubuntu): Permission denied (13)
pool/main/g/glibc-doc-reference/
pool/main/g/glibc/
pool/main/g/glibmm2.4/

Why wouldn't it be able to write to that directory? As mentioned
before, that entire directory path is owned by www-data:www-data. Am I
missing something here?