I started a game using the Stock New_World map script and Random Civs...

Got Dutch myself.
Found out later that England was not in the Game (spent like 15 minutes looking at the map in WB, because i couldn't believe it first...)

Made a few Random maps to try, and most of the time only 3 European Nations are present... Somehow this annoys me... (I would go as far as to call it a bug).

Is there any way to ensure all 4 European Countries are present, without presetting everything ?

Had the same issue yesterday, was playing a MP LAN game with a friend here at work. After a few rounds, well, more than a few, we kinda noted, that we were the only ones and the natives in the world... pretty boring. Do you really need to select the other European forces to get them in the game?

That is definitely wrong. If anything they could make an option for you to not have them in the game, but default they should be.

Yes, i think too.
From what i know about Civ4 maps scripts/SDK this is something that is hard to access for Modders, so perhaps Firaxis will need to fix it them self...

Actually, this isn't a bug and it's simple to change. If playing on LARGE and HUGE maps you get all 4 Euro nations. If you play on STANDARD or smaller you get less.

Here's the tags from Civ4WorldInfos.xml that are relevant:

iDefaultPlayers = Total number of player on map.
iDefaultNativePlayers = Number of tribes on map.

So obviously, iDefaultPlayers - iDefaultNativePlayers == number of Euros on map. :)

Ah thanks.