4.2.3 works for me Puntuado con 5 de 5 estrellas

I am indebted to BePaHa's review (please see below). I have Firefox 25, and Xmarks 4.2.1 was hanging. I installed 4.2.3 from the Xmarks download page, and now everything seems to be working okay. (According to another reviewer, 4.2.4 is out too, but I haven't tried it.)