http://sn.1w6.org/file/mk-20140228T161117-8y64ch8.html
@mk theory: Chromium is a resource hog (fact); when it's busy it seems to 'hold up' the mouse; when the network switch went on the fritz, chromium went bonkers - and the mouse could do nothing anymore. Or something like that. I've now restarted Chromium (lots of tabs), and every now and then the mouse gets stuck again...