FuBar_RecZone has not been code updated in a year (the author has gone). Consequently, its zone information currently is often inaccurate. And the last time I used it, it threw up errors in various zones.
FuBar_LocationFu is the currently maintained zone mod of this type; might want to try that instead. Has pretty much the same features as RecZone, but doesn't bug out, is updated and works fine with the current (Rock) FuBar.
As to FuBar mods "disappearing", need a lot more info in order to find out what the problem is. What version of FuBar are you using? Where did you get it from? Where are you seeing it disappear..in the Addons box in your character screen? Or trying to access it from FuBar? And so on.
Anyway, try FuBar_LocationFu from the above link. Installed properly (and used with the latest FuBar from here), it will work just fine.