error with thread

hi, list

on recently builded -current when i start X, portupgrade and some else 
programms I get a lot of this error:
"Fatal error 'Cannot allocate red zone for initial thread' at line 382
in file /usr/src/lib/libthr/thread/thr_init.c (errno = 12)", and 
coredump then.

googlin' give me feeling that it's good known sort of issue, but I 
couldn't find any example of soving

just where to look to solve it?

Regards, oleg