EU/CU Seed map generation changing

[Craigjw]

I played this seed (729685781) a couple of times in CU, however, it died when the EU patch came out, so thought I'd play again, however, this time, the map and vents had all changed, so I didn't bother.  I even triple checked the seed was exactly the same.  I thought just recently, that I'd see what vents there are and the map has reverted back to exactly how it was in EU.

Are there other factors to how a map is generated other than the seed value perhaps?

[Nutter]

I made a new map for EU.  Played 400 cycles on it then realized that I had made critical mistakes early on so I reloaded a save from cycle 100.  Played another 80 cycles before finding out that most of the key geysers on the map had changed!!!

I didn't even generate a new map or anything.  This is mid-season.  I can deal with having to restart every 6 weeks but this is very very not cool.