Deano,
As usual thank you so much for a prompt reply. Really apprisiate this. I managed to fix it applying the below:
1. Be sure that the forum module has the language compiled.
To compile the language, open in your browser "yourwebsite.com/forum/index.php?skin=uni" logged in as admin.
If the language is not compiled the text in the forum will have square brackets around every expression.
To compile the language, you will need to click "Compile language: En" link.
2. Open with your FTP application this path "yourwebsite.com/modules/boonex/forum/layout", you will find inside "uni" and "uni_en" folders.
Download the two folders to your desktop and rename the two folders to "template_name" respective "template_name_en".
Re-upload these two folders to the same folder ("yourwebsite.com/modules/boonex/forum/layout").
3. Clean the two cache folders: "yourwebsite.com/cache" and "yourwebsite.com/cache_public", delete all files inside except ".htaccess".
Worked like a charm!!! :)
I hope it will help someone in the future...