I didn't have to modify the user BackupPC or apache runs as but I did change the group on config.pl from backuppc to apache and that seems to work for me...
# ll /etc/BackupPC/
total 96
-rw-r-----. 1 backuppc backuppc 46 Jan 20 2013 apache.users
-rw-r-----. 1 backuppc apache 82263 May 11 19:45 config.pl
-rw-r-----. 1 backuppc apache 2293 Mar 26 13:29 hosts
-rw-r-----. 1 backuppc apache 0 May 28 14:00 LOCK
drwxr-x---. 2 backuppc apache 4096 Apr 29 07:31 pc
Thanks,
Richard
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