AMO experiencing technical difficulties

Since a long time , the "Add to Collection " function seems buggy:
When i open the “Add to collection” list:

  • Many labels are presents twice
    (maybe because i made an FR and an US version for some of them?).
  • The list came sometime with previous selected items (from a previous “add to coll” )
    (if i uncheck one of them, my original selected items come back)

Other request:

  • It’s possible to let the cursor at the last checked/unchecked action items
    and not to refresh the list and go back to the top of it ?

I am on firefox v.43.0.4 / Win7