I can't figure out how to keep all my the date/time information (in my calendar) from changing when I change my city location in the case of a time difference. For example, I set a meeting up in France for 14h00 (I am in Canada). When I change my city location to Paris from Ottawa (time difference of 6 hours), all my meetings have changed by 6 hours, too! Obviously, I'll be just a bit early (well, maybe not depending on the traffic) but you get the drift.
Your missing that it is a feature. In other words, if you don't want it to happen, don't change the clock home/current city; just use the world clock feature to show what the time is in the other country/timezone where you happen to be).
No other solutions/workarounds unless Nokia changes the behaviour, and if they do, until they release a firmware update with such a change for your phone (and until you upgrade to such a firmware version). Don't hold your breath while waiting.