Wonder of the World effects broken?

The population loyalty bonus of the Statue of Zeus wonder appears to be broken (or at least behaving radically differently than I expect it to). Has anyone else noticed a similar problem? Or perhaps someone can explain the bizarre behavior to me if I'm just misunderstanding how it is supposed to work?

The in-game description of the Statue of Zeus wonder says "The Statue of Zeus gives a +4 bonus to population loyalty in all settlements". When I look at the Show Settlement Details window of each city, the Public Order field has an icon labeled "Wonder" and a 20% bonus (regardless of local population). In the following turns, the bonus in each city drops to 15% in every city (simultaneously, again regardless of local population), then 10%, then 5%, and finally disappearing altogether. This is the second consecutive campaign I have noticed this behavior, so it does not appear to be a fluke. I still have the saved game files if anyone wants to study them.

The description of the wonder's bonus does not say anything about the loyalty bonus being temporary. Is there something I am missing here? the amount of the loyalty bonus was identical in each city, regardless of local population. I'm positive i'm not building something or doing something that causes the bonus to go away or be mitigated in some other way. The wonder is pretty useless if the effect is only supposed to last a few turns. If it is supposed to only be temporary, the description should make that clear.

Thank you for any insight anyone may be able to offer.

I've had the same thing. I think it's only temporary. That or maybe it's something we're doing wrong in the cities that cancel out the bonus. I'd like to hear anybody else on this just to be sure it's not me doing something wrong ~:)

They appear to be temporary and by design. I've captured the lighthouse of Alexandria and the Pyramids. The lighthouse went 20, 15, 10, 5, 0 while the pyramids are starting at 15. It is handy for taxing the heck out of your subjects for awhile though! Keeps population down a little in major cities and funds some major new construction before the effect wears off.

I'm glad it is only temporary. If having those things constantly gave a 20% bonus year after year it would be really abusable. Greece, Macedonia, the Seluecids and Egypt would all have huge advantages over anyone else.

Ah ok. I thought it would be only temporary. After all, no matter how great something looks or is it does wore off after a while

The "Wonder" item you see in settlement details is just a temporary 'morale' boost if you like for your people for capturing a wonder (any wonder). It wears off after a while. The actual bonuses that the wonders give you are permanent, but aren't specifically shown on the settlement details screen. The Zeus bonus is just factored in under 'happiness' or something.

At least, that's my understanding of it all.

Yeah I wondered how much the dominance of Egypt has to do with them having two wonders that they control.