Why doea a publishable document go "Out Of sync" in the broker??


I have a publishable document: DocA in IS1 which is “InSync” in the broker connected to IS1.
But after somtime if I check in the same broker the same document:DocA would have gone “out of sync”.

As far as i understand, A document goes out of sync if:

  1. changes are made to the publishable document:DocA
  2. changes are made to the broker document type of the document:DocA
  3. When the document:DocA is made publishable when the IS1 is not connected to its broker
  4. when the package containing the publishable docuemnt:DocA is installed to the IS1
    5.when the client group of IS1 is changed

But none of these cases have occured, But the document:DocA which is “InSync” goes “out of sync” after somtime

Can anyone of you please let me know the reson for this issue???

Thanks in advance!!!