Wrong water surface

[Zontik]

I've got problem with waterfall: its vertical surface suddenly started to look incorrect (as if I set wrong axles in Flood properties). But everything was done correct; surface was looking good for a long time, and even now it returns to normal condition after portalisation, but optimisation makes it look wrong again.
I will investigate and search for changes caused the bug (thanks to backup archive), but it will take a lot of time and I'm not sure about result. Are there any common methods to push Dark Engine to behave correct with water?
I tried to change brushes order; to move flood brush; to change axles to incorrect (why not?), to remove surrounding objects. Now I'm out of ideas.

[Ottoj55]

there is a flow brush around it? what are its settings? also some screen shots would help. and as an aside, i have a set of particles i use for waterfalls to simulate the spray at the bottom, a tutorial is on my site.

[Zontik]

OK, problem solved. One certain air brush was added later in a short distance from the waterfall (about 20 units). Of course, it didn't touch the waterfall brush - it was a kind of side effect. After removing that air brush everything came back to normal conditions.
Otto, I've already applied particles, the waterfall seems better with them.