Newbie confused with underline in files

Am new to using jdee and have just started finding my way around. One thing
that really confuses me is that
many files I open are underlined in red! I don't understand this. The syntax
is fine. The file compiles fine
without any issues but the red lines are still there.

My complete .emacs is below. Yes, the section related to JDEE has been
copy-pasted
from various sources :|.

Any pointers?

Thanks a ton!

(cond ((fboundp 'global-font-lock-mode)
       ;; Turn on font-lock in all modes that support it
       (global-font-lock-mode t)
       ;; Maximum colors
       (setq font-lock-maximum-decoration t)))
;;Default font
(set-default-font
"-outline-Verdana-bold-r-normal-normal-13-97-96-96-p-70-iso10646-1")
;;Default starting directory
(setq default-directory "D:\\")
;;Start Maximized
(w32-send-sys-command #xf030)
;;Transient mark mode
(transient-mark-mode 1)
;;Match Parens
(show-paren-mode 1)

;;JDE related stuff
(setq semantic-load-turn-useful-things-on t)
(load-file "F:/cedet/common/cedet.el")
(add-to-list 'load-path "F:/emacs-21.3/site-lisp/jde/lisp")
;;Lazy-load JDEE
(setq defer-loading-jde t)
(if defer-loading-jde
    (progn
      (autoload 'jde-mode "jde" "JDE mode." t)
      (setq auto-mode-alist
        (append
         '(("\\.java\\'" . jde-mode))
         auto-mode-alist)))
  (require 'jde))

(custom-set-variables
  ;; custom-set-variables was added by Custom -- don't edit or cut/paste it!
  ;; Your init file should contain only one such instance.
 '(jde-enable-abbrev-mode t))