Thank you for your time.. :-)
I am not sure if this issue seems to be very specific to the extension we are using. Joomla calls it's plugins as 'Extensions', this issue is regarding an extension named 'Zen Tools'. (zentools.joomlabamboo.com/grid)
We create pages using this extension to display images or individual articles in a Grid or Slideshow or any other possible layout.
This extension has filter settings through which i can define which images or which individual articles should be displayed in this Grid or Slideshow.
We have defined the filter in such a way to pull all articles (pages) which has been assigned a particular category (like Breaking News or Flash News.. etc)
Now even when all the following settings are correct, the output doesn't shows the articles
1) The Grid has the setting to fetch all articles belonging to 'News' category
2) Many articles (pages) are created and assigned the category as 'News'
3) The Grid, Articles & News are all in 'Published' status (there is an unpublished status in joomla where things will not be displayed in the site)
Strange thing is, 2 days back we created another set of Grid/Article/Category and that module is working perfectly fine. Lets assume that this working category is named as 'Films'.
As a next step, we modified the problematic grid filter to fetch articles of category 'Films' and the problematic grid started showing those articles in the website. But reverting it back to 'News' had the same problem.
We compared the settings between 'Films' and 'News' category and couldn't find anything different.
In the past 2 days, we hardly changed few lines in a css to reduce the height of a drop down menu.
So currently it's sort of clueless on what's happening behind the scenes when it comes to any categories we create since yesterday. All categories created before that seem to be working.