i have the same problem like one guy 1-2 pages ago; i read his posts about this problem but i can find a proper solution. I am desparate… Please Help :blah: :blah: :blah:
i am so near to the final version and i got this kind of mistake and know im very angry, … 
NeED HElP!
i made it and nothing happened, the same, 
i cant understand the root of this bug, thats the problem 
I just read in the LDR about the tracemap. Is the green channel of your tracemap, over the water bright or dark? Because it said that thin roofs will leak rain if they’re too thin…and dark in the tracemap. I guess over the water should be dark then? Disclaimer: I’ve never made a map for ET yet. 
I dont know the solution to the actual problem. But one way to get by this is to correct the tracemap in a paint program.
OHH GUYs, i solved the problem !!!.. i just replaced my tracemap with an older one, where everything was ok, and now i have rain over water… tnx this idea came to me when i was reading ur posts, so i solved the problem with ur help 