Arriving back from my motorbike week-end, I noticed 16 updates were available for RC1. I clicked on "select all" then "update" but nothing happened. Tried twice, just in case I made something wrong. Nothing again.
Suspecting something wrong, I unselected and then click for each and every package: bingo, once all packages were selected, I click on "update" and this launched the next step. So it looks like there is something strange here.
Next step: I got a nice window showing list of packages "to be installed" (sic).
Unfortunately, I was not able to click, at least using the mouse on any button because both were to low although I had scrolled down to the max already... another small itch or something wrong with my own firefox ?