gnome cannot start without kde

["Andrey S. Rybak" <ra@iop.kiev.ua>]

hi all!
I use gnome on testing branch of debian.
Some time ago next strange thing was happened.
In time of starting my computer i cannot achive even command prompt. 
Some infinite looping was occuring. But if i choose recovering regime  
of downloading there are no problem.
This infinite loop disappear if I install KDE. But i can achieve only 
command prompt and after running startx command I get gnome environment 
on my screen however.
If I deinstall kde the infinite loop are return.
I think there is problem with gdm3. But where I can look for resolving I 
dont know.
help me, please.