buffer tabs on X [?]

i'm using "XEmacs 21.5 (beta6) \"bok choi\" [Lucid] (i686-pc-linux) of Fri Apr 26 2002 on localhost" i tried to turn on the buffer tabs feature, but to no avail... is it possible that buffer tabs were disabled on X builds, as i vaguely remember? tia ======================================================================== here it is the Installation data: uname -a: Linux localhost 2.4.8-26mdk #1 Sun Sep 23 17:06:39 CEST 2001 i686 unknown ./configure '--extra-verbose' '--debug' '--use-union-type' '--with-clash-detection' '--rel-alloc' '--without-wmcommand' '--with-site-lisp=yes' '--with-athena=3d' XEmacs 21.5-b6 "bok choi" configured for `i686-pc-linux'. Compilation / Installation: Source code location: /home/gb/src/xemacs Installation prefix: /usr/local Operating system description file: `s/linux.h' Machine description file: `m/intel386.h' Compiler: gcc -g -O3 -Wall -Wno-switch -Winline -Wmissing-prototypes -Wsign-compare -Wshadow Relocating allocator for buffers: yes GNU version of malloc: yes - Using Doug Lea's new malloc from the GNU C Library. Window System: Compiling in support for the X window system: - X Windows headers location: /usr/X11R6/include - X Windows libraries location: /usr/X11R6/lib Using Lucid menubars. Using Lucid scrollbars. TTY: Compiling in support for ncurses. Compiling in support for GPM (General Purpose Mouse). Images: Compiling in support for GIF images (builtin). Compiling in support for XPM images. Compiling in support for PNG images. Compiling in support for JPEG images. Compiling in support for TIFF images. Compiling in support for X-Face message headers. Sound: Compiling in support for sound (native). Compiling in support for ESD (Enlightened Sound Daemon). Databases: Compiling in support for PostgreSQL. - Using PostgreSQL header file: pgsql/libpq-fe.h - Using PostgreSQL V7 bindings. Internationalization: Mail: Compiling in support for "dot-locking" mail spool file locking method. Other Features: Inhibiting IPv6 canonicalization at startup. Compiling in support for dynamic shared object modules. Using the union type for Lisp_Objects. Compiling in support for extra debugging code. WARNING: --------------------------------------------------------- WARNING: Compiling in support for runtime error checking. WARNING: XEmacs will run noticeably more slowly as a result. WARNING: Error checking is on by default for XEmacs beta releases. WARNING: ---------------------------------------------------------