error compiling gnome-panel-2.2.2.2 with gentoo 1.4

[L . Schmidt]

hi,
during compilation of gnome-panel, this message was displayed:

checking X11/extensions/Xinerama.h usability... no
checking X11/extensions/Xinerama.h presence... yes
configure: WARNING: X11/extensions/Xinerama.h: present but cannot be compiled
configure: WARNING: X11/extensions/Xinerama.h: check for missing prerequisite 
headers?
configure: WARNING: X11/extensions/Xinerama.h: proceeding with the 
preprocessor's result
configure: WARNING:     ## ------------------------------------ ##
configure: WARNING:     ## Report this to address@hidden ##
configure: WARNING:     ## ------------------------------------ ##
checking for X11/extensions/Xinerama.h... yes
checking for XineramaQueryScreens in -lXinerama... yes

the previous version was able to compile and run, although i'm not sure whether 
i might
have missed the error message then (this one was scrolling off the screen 
quickly)

*  gnome-base/gnome-panel
      Latest version available: 2.2.2.2
      Latest version installed: 2.2.2.1
      Size of downloaded files: 2,618 kB
      Homepage:    http://www.gnome.org/
      Description: The Panel for Gnome2

the system i was compiling gnome-panel for is indeed a Xinerama-configured 
system.
and the resulting executable seems to work ok.