Why does a maildir resync take 4mn? (maildir_header_cache_verify = no)

[Marc MERLIN <marc_mutt@xxxxxxxxxxx>]

[no luck on mutt-users, trying here]

I have
set     folder="~/Maildir/"
set     header_cache="~/Maildir/"
set     maildir_header_cache_verify = no

The header cache definitely helps, I can open a 40,000 message maildir in
seconds instead of several minutes.
However, if the parent directory of the folder I'm viewing, gets modified
(let's say I'm in ~/Maildir/.snd/ and I send a new mail), mutt takes a silly
time to resync the folder, like 4mn for 40,000 messages.

Is there anything I can do to make mutt more bearable in this case like this?
Why is mutt resyncing everything when I do have maildir_header_cache_verify
set to no? What else can I do to stop this?

I have Mutt 1.5.13 (2006-08-11)
-DOMAIN
+DEBUG
-HOMESPOOL  +USE_SETGID  +USE_DOTLOCK  +DL_STANDALONE  
+USE_FCNTL  -USE_FLOCK   +USE_INODESORT   
+USE_POP  +USE_IMAP  -USE_GSS  -USE_SSL_OPENSSL  +USE_SSL_GNUTLS  +USE_SASL  
+HAVE_GETADDRINFO  
+HAVE_REGCOMP  -USE_GNU_REGEX  
+HAVE_COLOR  +HAVE_START_COLOR  +HAVE_TYPEAHEAD  +HAVE_BKGDSET  
+HAVE_CURS_SET  +HAVE_META  +HAVE_RESIZETERM  
+CRYPT_BACKEND_CLASSIC_PGP  +CRYPT_BACKEND_CLASSIC_SMIME  -CRYPT_BACKEND_GPGME  
-BUFFY_SIZE -EXACT_ADDRESS  -SUN_ATTACHMENT  
+ENABLE_NLS  -LOCALES_HACK  +COMPRESSED  +HAVE_WC_FUNCS  +HAVE_LANGINFO_CODESET 
 +HAVE_LANGINFO_YESEXPR  
+HAVE_ICONV  -ICONV_NONTRANS  +HAVE_LIBIDN  +HAVE_GETSID  +USE_HCACHE  
-ISPELL

Thanks
Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems & security ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/