This is probably related to bug #569.

Retrieving a note when the note contains a dot causes a
segmentation fault.  Script to reproduce:

<?
apache_note('asdf', 'asdf.qwer');
apache_note('asdf');
?>

The second call to apache_note() will crash with this
backtrace:

Program received signal SIGSEGV, Segmentation fault.
0xaf41 in _efree (ptr=0x2290b4) at alloc.c:169
169             REMOVE_POINTER_FROM_LIST(p);
(gdb) bt
#0  0xaf41 in _efree (ptr=0x2290b4) at alloc.c:169
#1  0x7c8b in yystype_destructor (yystype=0xefbfcc5c) at variables.c:88
#2  0x3891f in phpparse () at language-parser.y:470
#3  0x4af6 in php3_parse (yyin=0x201eb5e0) at main.c:1442
#4  0x4e20 in apache_php3_module_main (r=0x228034, fd=18, 
    display_source_mode=0, preprocessed=0) at main.c:1822
#5  0x1808 in send_php3 ()
#6  0x186c in send_parsed_php3 ()
#7  0x9ab47 in ap_invoke_handler ()
#8  0xb0a29 in process_request_internal ()
#9  0xb0a7f in ap_process_request ()
#10 0xa7bf5 in child_main ()
#11 0xa7e48 in make_child ()
#12 0xa8286 in perform_idle_server_maintenance ()
#13 0xa88b9 in standalone_main ()
#14 0xa8e53 in main ()