Hi,
I think I am currently experiencing this issue. All my GET requests (with 2 different app) to home_timeline, mentions result to a 401 response while POST requests like update works fine (with the same credentials)
Same weird behaviour with realtime API : userstream/user --> 401 but stream/filter --> 200
With another account (so other credentials), but on the same computer (& same app) all work fine.
Finally, looking at my users, today is the worst day with a lot of 401 responses on userstream/user ( 5 times more than yesterday ).
Please help.