Yeap, it's working again ... for the most part. What is happening now though is when the last tab fills the first row, the next tab still doesn't show. You need to open one more (making it 2 in total), then those 2 tabs roll onto the next (second) row. This happens only with the first row.
^ this happens from time to time, like when tabs rolled onto the second row. I reloaded them all and they all became normal. It also happened once when i closed a tab.
I see this too but I have a reproducible way to cause it. Also there is another bug that is revealed by the STR.
1) Fill up the 3 rows of the Multi-Row tab bar (3 being the default)
2) Add another tab and suddenly all tabs end up in a row of favicons that overlap each other. Looks a bit like AppTabs just that there is no real tab border and the favicons are overlapping. This is certainly a bug.
3) Remove so many tabs that the amount of tabs would fit into a 3 row Multi-Row tab bar and you end up with tabs as in the picture above.
Mozilla/5.0 (Windows; Windows NT 5.1; en-US; rv:2.0b2pre) Gecko/20100706 Minefield/4.0b2pre ( .NET CLR 3.5.30729) ID:20100706040808
Edit: Sometimes Step 3 doesn't happen and you get the proper Multi-Row tab bar again but if you persist and try it several times it will eventually show.