I was feeling the same thing on a run last week with dedpigeon was happily attackin bends except the down hills I knew I was doing it but was having an off day and couldn't help it, to me it was a loss in confidence of front end grip.
When on the up hill you can get on the power thus loading up the rear tyre and increasing the turn in gyroscopic effect, when on the down hill though, your backing off in your head, this leads to backing off the throttle and loading up the front end, whilst also making the bike want to sit up, add to this an adverse camber and it can lead to disaster.
Best thing to do in this instance for me is just back off the pace a little, don't attack the bend make sure you've done your breaking before turning in and get on the power even if its just a steady throttle, practice on the corner if its bugging you till you get the confidence back.
Works for me at any rate
