Building XFce 4 modules depends on :
pkgconfig, a system for managing library compile/link flags that works with automake and autoconf.
GTK+ >= 2.0.6 (also dev packages), the GIMP multi- platform toolkit designed for creating graphical user interfaces.
libxml2, a XML C library developed for the Gnome project.
libdbh, the "Disk based hashtables" library, is needed for xffm, the file manager.
v obshem prover est' li u tebya gtk-devel package, rpm -aq|grep gtk i tam uvidish, esli net, to postav ego s rh9 cd i vse dependencies toje dostav chego net u tebya.. a potom zanovo xfce stav

best wishes
Добавлено через 2 минуты:
aaa zabil sovsem, pro podskazki, vot eto postav, i budet rabotat'
Optional dependencies :
librsvg >= 2.2.x, a SAX-based renderer library for SVG files, that has to be installed if you want to use SVG icons for the panel.
libstartup-notification >= 0.5, a library that has to be installed if you want to use the startup notification feature.
PS:
http://xfce.org/en/overview.html RTFM i nikogda ne zabivay chitat doki pered tem kak chto to stavit...