Usage case study, difficulties and solutions

Here's a case study of how I am using this module, areas where I have encountered problems and some solutions.

The project is for an international organisation that wishes to have multi-lingual content. They have international volunteers who translate work and submit this to the site administrator. This is currently done in word documents and the task is extremely labour intensive as everything they have currently setup is static. Administrator has to manually add the content and archive files etc. They have over 3000 static documents in english which are currently being translated into several languages. A new english document is added everyday and translations come through everyday from around the world. Furthermore there is an international community with groups in many countries. More being added everyday.

The project goals: to allow volunteers to login and translate indexed content from English and to have a way of communicating with volunteers via a volunteer home page; to have home pages for each language group themed to present content for that particular language; scalable to take on more volunteers and languages; search engine friendly; nurture and grow the community around each language group with user profiles and user submitted content per language group (forum, comments etc.).

The solution I am looking at is to use localizer and drupal multi-site setup along with cck, views to handle presentation of languages on multiple-domains and possibly og module to manage groups. I've setup a database and 1 main domain for english and 4 subdomains (de,it,es,tr). In order to have flexibility with theming and share content as well as user info accross the sites I used the following multi-site config...

1 database with all tables shared except the cache and variable tables. Therefor I have:
tr_cache
tr_variable
es_cache
es_variable etc.

Within each site/sub-domain folder I have the settings.php files configured with corresponding base_url and table prefix settings. Here is an eg.

   $db_prefix = array(
     'default'   => '',
     'cache'     => 'de_',
     'variable'  => 'de_',
   );

The above setting works for D5.x (previously each shared table had to be listed as opposed to each unique domain table).
I've followed the handbook suggestions for file and folder setups and have placed all shared modules in the site/all directory, where the localizer module also happens to be. I have seperate theme folders for each sub-domain.

Some areas where I am having a tough time...

numerous cache errors...cache table unlocked
Table 'cache' was not locked with LOCK TABLES query: UPDATE cache SET data = 'a:0:{}', created = 1170297261, expire = 0, headers = '' WHERE cid = 'locale:en' in /home/domain/domains/domain.com/public_html/includes/database.mysql.inc in Zeile 172.

cannot modify headers
Cannot modify header information - headers already sent by (output started at /home/zenmate/domains/zenmate.com/public_html/includes/database.mysql.inc:172) in /home/zenmate/domains/zenmate.com/public_html/includes/common.inc in Zeile 311.

When I had one database with all shared tables, I was unable to switch back to the original english language after switching to other sub-domain languages. So I thought this had to do with caching which lead to me creating seperate cache and variable tables for each sub-d. After doing this I started getting the above mentioned errors...cache unlocked and cannot modify headers.

I've got cck installed, localizer, views and pathauto. When I disable localizer the above mentioned errors go away.

Now I understand that these errors are more likely to do with a combination of factors. I am no coder so cannot really interpret what's happening with the error logs.

Have you managed to test localizer on a setup with different hostnames and one db? Is the above setup achievable? Or will I have to look at another way of solving. Any suggestions and comments from the module developer and community will be much appreciated. Thank you Roberto for your consistent effort so far! I feel that once localizer starts to have some documentation to assist with scenarios and questions like the above, it will be a much desired and used tool within Drupal. Maybe it will even find its way into core.

I will be happy to assist with writing out the documentation for the above scenario once we find a solution...whew long post...i've got to get a piano!