FC4 (2.6.13) SMP multithread coredump missing second thread register state

Hi,

Running a multi-threaded application on FC4 (2.6.13) SMP with GLIBC 2.3.6 NPTL 2.3.6.
When I force a crash of one of the threads (sleep followed by an illegal reference or an abort()), the resulting coredump does not have the correct values of the second thread's register set in it (readelf and objdump just show zeroes in that Note).
I infer that the kernel (binfmt_elf.c et alia) may not be able to get the state of threads running on a different CPU than the thread getting the exception.
Is this a known limitation of 2.6, or is there some sort of config directive required to enable dumps of multiple threads in a multi-cpu configuration?

More than happy to provide additional information, I just don't want to clutter the message. Just tell me what would help.

Thanks.