How the function package-installed-p should behave on emacs startup if
some package is already installed? It seems that it returns nil for
installed package on emacs startup.

Here is the full .emacs file (used for this test):

(require 'package)
(message "**** auto-complete is installed: %s ****" (package-installed-p
'auto-complete))

auto-complete package is installed for this moument, but during emacs
sturtup *Messages* buffer shows:

**** auto-complete is installed: nil ****

But after sturtup the evaluation of the expression

(message "**** auto-complete is installed: %s ****" (package-installed-p
'auto-complete))

returns:

**** auto-complete is installed: t ****

But how it is possible to install just not already installed packages on
startup. For this moument all packages are re-downloaded and reinstalled
for me during every emacs startup.


In GNU Emacs 24.2.1 (i386-mingw-nt5.1.2600)
 of 2012-08-29 on MARVIN
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.6) --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include'

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: RUS
  value of $XMODIFIERS: nil
  locale-coding-system: cp1251
  default enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<menu-bar> <buffer> C-a <help-echo> <help-echo> <help-echo>
<menu-bar> <file> <open-file> <help-echo> <help-echo>
<tool-bar> <open-file> <down-mouse-1> <mouse-1> C-x
C-e <help-echo> <help-echo> <menu-bar> <buffer> C-a
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <menu-bar>
<help-menu> <send-emacs-bug-report>

Recent messages:
**** auto-complete is installed: nil ****
memoize-wrap-frame-local: Symbol's function definition is void: gensym
Quit
Loading vc-git...done
**** auto-complete is installed: t ****
"**** auto-complete is installed: t ****"

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail regexp-opt rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils vc-git finder-inf package
tabulated-list time-date tooltip ediff-hook vc-hooks lisp-float-type
mwheel dos-w32 disp-table ls-lisp w32-win w32-vars tool-bar dnd fontset
image fringe lisp-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev minibuffer loaddefs button faces cus-face files text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process multi-tty emacs)