Still Irritated Only More So!!! Answered
Apparently another problem is not being able to reply to comments. This is the fifth attempt to do so; this time I will try a new topic rather than a reply. When I reply, and click "Post", I get an "Oops, your session has timed out" message, and am dumped back onto the logon page - I believe that's the twenty-third logon today so far! There it says "After you log in, we'll send you on your way to: 'edit/post' ". I log on (again) and am taken to a blank page. Let me add that one of these "time outs" occurred exactly 19 seconds after I had logged on!
In reply to the comment from randofo - I am indeed using IE8, with internet security set to medium-high. Cookies are enabled.
I have searched the forums and tried what "fixes" I found to no beneficial result. One of those suggested removing all security, which I tried very briefly. No help.
I occasionally use private browsing mode, but not at instructables.com.
In reply to caitlinsdad, thanks for the helpful comment. When a site charges for a service, they have declared themselves to be professional and need to accept those standards.