Hmm, someone should ask plesk about this, I'd imagine there is a setting somewhere in it that allows the umode to be set. Generally, you would set the users umask for web to be 022 (User read/write/execute, Group read, world read). However it sounds like plesk is setting the umask to 110. That's not what I would call a good web environment. If you change the system bashrc (usually /etc/bashrc) to a more sane setting, it will work better. However there is also the possiblity it is being set in the user bashrc (~/.bashrc) in which case you would change the /etc/skel/.bashrc (notice the period there!) Here is a snip of a bash RC:
if [ "`id -gn`" = "`id -un`" -a `id -u` -gt 99 ]; then
The second umask is the users, the first is for system accounts. Also, it may be stored in the /etc/profile or ~/.bash_profile files.
When HCL creates the directory, who owns the files (apache or httpd or