'miraculous' re-centering on the bottom line

[Zeitlinie]

Hi,

I'm running emacs 24.4 & 24.3 and experience some kind of 'automatic' 
re-centering issue which drives me completely nuts and make editing a pain.

I have several windows open (actually with ecb-activate, working on some 
project). Now, while I edit a file, and at random intervals of the order 
of some seconds length, the line I currently work on *jumps* to the 
bottom of the window I am just working in - as if some wizard in the 
background would have executed C-l three times.

I consulted Dr. Google for similar issues and only found that maybe 
setting auto-window-vscroll to nil might help.
I did that - unfortunately with no effect.

Does anyone around here know what this re-centering might be due to and 
how to stop emacs from doing it?

Mark