Hi,
After further investigation, a proper solution was still not found for this issue.
I have tried customizing the SEF URL as suggested by jan but that didn't do the trick.
Even after removing all the SEF urls including custom SEF and 301 redirects, the issue was not resolved (cache was cleared too when tested).
The page loads fine when I change the Artio's content extension setting to use JoomSEF basic rewrite or Joomla Core, however the url does not output as desired (JoomSEF basic rewrite adds article/articleid at the end)
Does anybody have any idea what could be causing the issue?
The website is running latest Artio for Joomla 1.5