Currently, when you comment a long text the entire session time out and you get unable to upload the edited file.

If one did add a Ajax timer control, as the sample in http://ajax.net-tutorials.com/controls/timer-control/, it would make the session exist as long as the user / teacher did edit the documents.

If the Ajax timer is applied only in the DirectEdit-section, then only the editing function would be affected. When the user goes to another section of It's Learning or close the browser then the timer will not update - and you would get the normal timeout as usual.