had a similar problem, maybe it's the same
the program seems to be crashed, and I wait a really .. really long time, I'm sure i have over 4k bookmarks, 1k+ speeddials and other saved info, so after sometime passed.. more than an hour or even much more, the sync is finished, next time it starts in a normal way, just as before
i donno what is causing it, because this never happened before version 62