Importing grains from Add-ons

Something is intermittent here
First the import using add-ons works

I was adding the add-on list one by one.  Initially the Item I was adding was not disappearing from the add-on list, despite a message that said the add was successful.
Then it started acting "Normally", with the addition "deleting" from the list as expected. 
After I had added several (most) successfully, the entire list reappeared, including all those that I had added.

Hi,
  It sounds like some kind of screen refresh problem - I've not seen it here but I'll play around and see if I can get it to occur.

Brad