Description:
Despite the fact that mutt was compiled with +USE_SASL the authenticator CRAM-MD5 isn't used.

Additional info:
* package version
Mutt 1.5.20 (2009-06-14)

System: Linux 2.6.30-ARCH (x86_64 and i686, both affected)
slang: 20104
hcache backend: GDBM version 1.8.3. 10/15/2002 (built May 10 2009 07:52:18)
Compile options:
-DOMAIN
-DEBUG
-HOMESPOOL -USE_SETGID +USE_DOTLOCK -DL_STANDALONE +USE_FCNTL -USE_FLOCK
+USE_POP +USE_IMAP +USE_SMTP
+USE_SSL_OPENSSL -USE_SSL_GNUTLS +USE_SASL -USE_GSS +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
-EXACT_ADDRESS -SUN_ATTACHMENT
+ENABLE_NLS -LOCALES_HACK +HAVE_WC_FUNCS +HAVE_LANGINFO_CODESET +HAVE_LANGINFO_YESEXPR
+HAVE_ICONV -ICONV_NONTRANS -HAVE_LIBIDN +HAVE_GETSID +USE_HCACHE
-ISPELL
SENDMAIL="/usr/sbin/sendmail"
MAILPATH="/var/mail"
PKGDATADIR="/usr/share/mutt"
SYSCONFDIR="/etc"
EXECSHELL="/bin/sh"
-MIXMASTER


* ldd /usr/bin/mutt
linux-vdso.so.1 => (0x00007fff0fb18000)
libslang.so.2 => /usr/lib/libslang.so.2 (0x00007fa22bc38000)
libm.so.6 => /lib/libm.so.6 (0x00007fa22b9b6000)
libssl.so.0.9.8 => /usr/lib/libssl.so.0.9.8 (0x00007fa22b767000)
libcrypto.so.0.9.8 => /usr/lib/libcrypto.so.0.9.8 (0x00007fa22b3d9000)
libz.so.1 => /usr/lib/libz.so.1 (0x00007fa22b1c4000)
libsasl2.so.2 => /usr/lib/libsasl2.so.2 (0x00007fa22afab000)
libgdbm.so.3 => /usr/lib/libgdbm.so.3 (0x00007fa22ada6000)
libgpgme.so.11 => /usr/lib/libgpgme.so.11 (0x00007fa22ab72000)
libgpg-error.so.0 => /usr/lib/libgpg-error.so.0 (0x00007fa22a96f000)
libc.so.6 => /lib/libc.so.6 (0x00007fa22a61c000)
libdl.so.2 => /lib/libdl.so.2 (0x00007fa22a418000)
/lib/ld-linux-x86-64.so.2 (0x00007fa22bf8b000)
libresolv.so.2 => /lib/libresolv.so.2 (0x00007fa22a202000)
libcrypt.so.1 => /lib/libcrypt.so.1 (0x00007fa229fcb000)

Everything seems to look fine. Linked against SASL, so CRAM-MD5 should work as authenticator. But it falls back to LOGIN, so push it:

* .muttrc contains:
set imap_authenticators="CRAM-MD5"

dovecot logs:
dovecot: imap-login: Aborted login (no auth attempts): rip=127.0.0.1, lip=127.0.0.1, TLS

Checked with mutt from a debian system:
dovecot: imap-login: Login: user=<foo>, method=CRAM-MD5, rip=<IP>, lip=<IP>, TLS

mutt -v on the debian system gives

Mutt 1.5.18 (2008-05-17)
Copyright (C) 1996-2008 Michael R. Elkins and others.
Mutt comes with ABSOLUTELY NO WARRANTY; for details type `mutt -vv'.
Mutt is free software, and you are welcome to redistribute it
under certain conditions; type `mutt -vv' for details.

System: Linux 2.6.26-2-686 (i686)
ncurses: ncurses 5.7.20081213 (compiled with 5.7)
libidn: 1.8 (compiled with 1.10)
hcache backend: GDBM version 1.8.3. 10/15/2002 (built Oct 20 2002 20:32:18)
Compile options:
-DOMAIN
+DEBUG
-HOMESPOOL +USE_SETGID +USE_DOTLOCK +DL_STANDALONE
+USE_FCNTL -USE_FLOCK
+USE_POP +USE_IMAP +USE_SMTP +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
-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
SENDMAIL="/usr/sbin/sendmail"
MAILPATH="/var/mail"
PKGDATADIR="/usr/share/mutt"
SYSCONFDIR="/etc"
EXECSHELL="/bin/sh"
MIXMASTER="mixmaster"
To contact the developers, please mail to <mutt-dev@mutt.org>.
To report a bug, please visit http://bugs.mutt.org/.

patch-1.5.13.cd.ifdef.2
patch-1.5.13.cd.purge_message.3.4
patch-1.5.13.nt+ab.xtitles.4
patch-1.5.4.vk.pgp_verbose_mime
patch-1.5.6.dw.maildir-mtime.1
patch-1.5.8.hr.sensible_browser_position.3

Please check.