I experienced issue #948 in Seamonkey/Linux too, but after updating to 1.3.6, there is a new twist: if I exit the browser and start again, the filter list is empty like in #948: http://i.imgur.com/iudHGm5.png
If I reset the settings to the defaults, the filter list is populated again and everything works until the browser shutdown.

There is "vAPI.cloud is undefined" error in the console when selecting the empty filters tab: