The checkbox in the Weave prefs to enable/disable history sync doesn't seem to do anything.
No, and this can unfortunately have the effect that syncing can take much longer than needed. Greatly appreciated if someone can take a look at this as the problem should not be very hard to fix (as far as I can see).
It does now! Try the latest developer snapshot: https://labs.mozilla.com/forum/index.php?topic=544.0