I have a number of users on some of my more high traffic sites that a running into problems with modifying their documents. It seems ( regardless if they use the check out/check in progress) if they open a document and start editing it ( I've had them check to see if they were opening up a read only version) and try to check it back in it will drop the document connection to the team site but this does not happen every time. I ve done extensive testing to try to replicate this and found that if someone clicks on a document while someone else is editing the document this will happen. Has anyone ran into this problem before? If so, can you please share a work around? Any help or suggestions would be truly appreciated.