This may be my fault -- a problem with apache_note() but I'm not sure. I can call it some places with no problem, but one particular call of

apache_note("sessionID",$some_integer)

results in a segfault with backtrace like:

Program received signal SIGSEGV, Segmentation fault.
0x809ad4d in _efree (ptr=0x8260e74) at alloc.c:169
169             REMOVE_POINTER_FROM_LIST(p);
(gdb) bt
#0  0x809ad4d in _efree (ptr=0x8260e74) at alloc.c:169
#1  0x809811b in yystype_destructor (yystype=0xbfffef44) at variables.c:87
#2  0x80bef01 in phpparse () at control_structures_inline.h:1444
#3  0x80950d0 in php3_parse (yyin=0x82622c8) at main.c:1419
#4  0x8095390 in apache_php3_module_main (r=0x826006c, fd=20, 
    display_source_mode=0, preprocessed=0) at main.c:1824
#5  0x8092b4c in send_php3 ()
#6  0x8092bb0 in send_parsed_php3 ()
#7  0x80c62a3 in ap_invoke_handler ()
#8  0x80d76e5 in process_request_internal ()
#9  0x80d7724 in ap_process_request ()
#10 0x80cfe09 in child_main ()
#11 0x80cff78 in make_child ()
#12 0x80d00db in startup_children ()
#13 0x80d06b8 in standalone_main ()
#14 0x80d0e23 in main ()
#15 0x8069b0b in _start ()