bearerbox doing mysterious things in gwthreadsleep

hy... I've read of many users having trouble with bearerbox eating all memory & cpu.
now i've got such a problem for myself too.

it's a plain setup with one ucp connections.
It sits on a sarge box.

I've atached to it with gdb to find out, that it starts consuming memory and cpu while it is Sleeping!

the gwthread_sleep function, in the line where it actually 
sleeps:
    ret = poll(&pollfd, 1, milliseconds);
(line 750 in my case)
Because of i've not yet done much with the threadding 
stuff, can somebody help me on that point?
What kind of file does it poll?
What could go wrong here?

Tia, Wilfried Goesgens