Seg faults

I'm not sure how to debug this one:

core was generated by `/home/kle/plapache2/bin/httpd -k start'.
Program terminated with signal 11, Segmentation fault.
#0 apr_brigade_writev (b=0x817e310, flush=0, ctx=0x0, vec=0x817e350, nvec=24)
at buckets/apr_brigade.c:478
/home/kle/plhttpd-2.2.4/srclib/apr-util/buckets/apr_brigade.c:478:14731:beg:0xb7ef5565
(gdb) bt
#0 apr_brigade_writev (b=0x817e310, flush=0, ctx=0x0, vec=0x817e350, nvec=24) at buckets/apr_brigade.c:478
#1 0x080956df in ap_http_header_filter (f=0x817d930, b=0x817e298) at http_filters.c:627
#2 0x0806e767 in ap_content_length_filter (f=0x817d918, b=0x817e298) at protocol.c:1338
#3 0x08096875 in ap_byterange_filter (f=0x817d900, bb=0x817e298) at byterange_filter.c:177
#4 0x080728cc in default_handler (r=0x817cba0) at core.c:3740
#5 0x0807a7a9 in ap_run_handler (r=0x817cba0) at config.c:157
#6 0x0807da37 in ap_invoke_handler (r=0x817cba0) at config.c:372
#7 0x080944f2 in ap_process_request (r=0x817cba0) at http_request.c:266
#8 0x080916cb in ap_process_http_connection (c=0x8170be8) at http_core.c:187
#9 0x08081a09 in ap_run_process_connection (c=0x8170be8) at connection.c:43
#10 0x080a7b6c in child_main (child_num_arg=) at prefork.c:652
#11 0x080a7ee7 in make_child (s=0x80d4c80, slot=2) at prefork.c:752
#12 0x080a7fa4 in startup_children (number_to_start=3) at prefork.c:770
#13 0x080a8b43 in ap_mpm_run (_pconf=0x80d00a8, plog=0x810e1a0, s=0x80d4c80) at prefork.c:998
#14 0x08066db5 in main (argc=135061792, argv=0x0) at main.c:717