It's currently set to log users out after 20 minutes of inactivity, and I doubt that number will be increased, nor should it be. Users that type out very long posts or that are very slow typists should probably click the "remember me" box to avoid this issue. Forums such as this one are not meant for extremely long posts, or articles, but are meant for problems and solutions that are more direct and to the point.
Of course, if the "remember me" box is not working correctly that would be a different matter, but it seems to be working fine on my end.

