Thanks Lori for taking out time and replying to my query.
Yes, I am able to see these documents when i am changing the view as 'documents' or 'contents' but not in case "All".
Also ,when i am trying to customize the All view and checking all the document types ,the modifications are not saving up and it is again showing the same old document types but not the new ones.I have created a Save as view of All by the name "All Objects" and in that i am able to customize and all the document types are visible in this case.I assume there is some issue with the OOTB "All" view but not sure what it is.
can it be related to some databse corruption?
Regards
Samresh