Error 503 nstallation on Mediatemple hosting service

[sgotte]

Hello,
I am trying to install MantisBT in my MediaTemple account and I'm seeing a page with the heading "503: Service Unavailable" and stating "Making Things Better. Sorry! We are tinkering in the background and making improvements...."
I have been unable to complete the installation and begin my first Mantis project on this server - though I have done this a couple of times before without issue on a single-user, personal Windows laptop. Here are the steps that I have followed:
- Untarred the MantisBT software in the main html directory for my server, (filename mantisbt-1.2.10.tar.gz).
- Renamed the resulting directory from the untarring from mantisbt-1.2.10 to mantisbt to be more user friendly. (BTW, I get the same error if I leave the name alone).
- Created a database with a separate user account and password in my MediaTemple account.
- Tried reaching the url http://www.mydomain.com/mantisbt/admin/install.php - I get the Error 503 here instead of seeing the normal page.
- Renamed the original config_inc.php.sample to config_inc.php and edited the following entries:
$g_hostname = '****MYSERVER****';
$g_db_username = '****MYUSER****';
$g_db_password = '****MYPASS*****';
$g_database_name = '****MYDB****';
$g_db_type = 'mysql';
The only caveat, here is that in my case, my DB name has to be like 'DB1234_bugtracker' and the username 'DB1234_bugtrackerusername' in order to comply with MediaTemple - I'm not sure if that's of any significance.
Also, in case this is important, I get the same error when I try to go to http://www.mydomain.com/mantisbt/. My website, http://www.mydomain.com is fine of course.
Another thing that may assist you to assist me is that, when I shell into my web server, I get this as the first line:
Linux n16 3.2.6mtv10 #1 SMP Wed Apr 4 09:28:15 PDT 2012 x86_64

Does anyone know how I can fix this Error 503? Also, is there some sort of hidden log file somewhere where I can see more detailed error messages?
Thank you for any assistance you may provide,
Simon

[sgotte]

If anyone has the same trouble in the future, the solution for me was to chmod 755 the folder in which mantisbt was installed on the server.