I had a similar bug, for one turn the Arcean's influence was so high that the whole map was yellow and the ip ratio on the planets was about 130 and I got all kinds of warnings about rebellions.
Fortunately one turn later all was back to normal. (and no, I neither saved nor loaded the game at any point).

This happened to me as well against the Altarians. Only lasted one turn (woah @ 30k ratios of IP) and all was normal afterwards.

I saw something similiar twice today. Both times, for a turn, the terrans suddenly controled the entire map. Both times Drath planets flipped to the terrans and the Drath were esentially destroyed. It would then go back to normal on the next turn or so.

Same thing happened to me. Got a cultural victory. I was in the middle of the universe andi build the Restaurant of Eternity. The a random event saying that people like foreing stuff pop up and BANG almost all the galaxy was under my color. 10 turn later I won. Of course it was on a small map but i think the multiplier or something is not right with this event. I won the game but it feel like a cheap victory. I didn't really sweat to obtain it...

I have just noticed another bug IN THE SAME GAME! In Foreign Policy under the UP tab the Korx and the Drengin who are both eliminated still show up as UP voters along with a healthy perecentage of votes. Woa! I guess this after the influence flood everything went crazy....

I had very similar behaviour in a game. The entire map was instantly flooded in Arcaen yellow. The IP ratio on my home planet was 539 or so. Next turn it was gone. It's caused a problem in the game though, because they flipped my best planet in that one turn.

So, my guess is they use an unsigned int to hold planet population. At some point in the invasion sequence, the planetary population gets set negative. Since it's unsigned, the negative wraps around and BLAMMO! There's probably even some code that tries to set the floor to zero or one, but since it's unsigned, that doesn't work (the damage is already done). I don't like using unsigned because it's unintuitive that way.

For the one turn they have huge population (so influence), then more than 4 quadrillion of the new citizens starve to death in a weak

I don't think my case was a population spike, because the population graph didn't change like the influence graph did.

I figured out why i couldn't win a diplo victory: Before i started the game i selected the Arceans, the Drengin, the Korx and the Torians as my rivals. When the game began i wasn't happy with my starting position and i regenerated the map multiple times (i did a lot of saves and loads at this stage as well). At some point weird things started to happen:
Sol was shown like any other random star system, meaning there was no mars and jupiter and the rest but Sol III, Sol IV etc. Only Earth had the same name but different interface. Also at some other point when i was finally happy with my position i noticed that the Torians weren't in the game! I ignored that and pretty soon i forgot about it until i had to make an alliance with them in order to win!

In short: it should be a reproducable bug.

This is the much loathed "invasion population" or "invasion cheese" bug. having 900trillion people on one planet ups it's influence, making you the influence king! It's being worked on i'm sure

I have the same problem, anyone have an email addy I can send a save game to?

Reloading does not work in my case. I also am not the one with the cheesy sphere of influence, it's one of the enemy A.I. dudes. They were taking over another enemy A.I.'s planets and everything seemed normal until they took over the planet of a minor race (Snathi) and had an instant influence explosion. I can see the planet's pop. & approval rating (which are "normal") but do not have a high enough level of intel to be able to see what improvements are on the planet, which is why I asked if there was somewhere I could email a saved game.