When I saw the title, I thought "Oh, finally someone who knows!"
Since when I had IC1 in 1.7.3, I always gen'd the SMP map with the seed "gargamel" and I always went to that epicly huge cave with epicness (Always were 6 diamonds etc.) but I noticed between the 5-6 maps I gen'd that sometimes things were different, like there were waterfalls where there weren't, or there was a lavafall were it indeed wasn't supposed to be (According to the vanilla map) and It was weird. I still got my 6 diamonds each time
Yeah I still think IC2 does something to terrain as when I used the Xray in MCEdit and it took me a few minutes to find diamonds, where on a normal world I can find them almost instantly. Now I'm on Singleplayer Technic pack 1.8.1 and I've found 6 diamonds already (or I should have, but a certain Mr. Creeper took them before I could ;)). Though back to the point somethings definitely up with the terrain generation. Also I did not know about that seed so next time I start a world I know what to use