external widget: events lost

Keyboard events from external client window do not reach xemacs (XtAppProcessEvent inside xemacs does not return). Mouse events are OK (XtAppProcessEvent returns and all keyboard input handled properly). When I use Xt external client, keyboard events are always lost. When I use Xm external client, initially this also happens, but after some mouse actions in client window it inpredictably becomes OK. Client program is always the same, it is just linked with different libextcli. X environment: x11 5, motif 1.2 (SCO xds 5.2.5h, SCO BaseX 5.1.1b) `Installation': uname -a: SCO_SV d-fens 3.2 2 i386 ../xemacs-21.1/configure '--compiler=gcc-2.95.2' '--prefix=/usr' '--debug' '--error-checking=all' '--external-widget' '--with-socks' '--verbose' XEmacs 21.1.12 "Channel Islands" configured for `i586-unknown-sco3.2v5.0.2'. Where should the build process find the source code? /home/gin/xemacs-21.1 What installation prefix should install use? /usr What operating system and machine description files should XEmacs use? `s/sco5.h' and `m/intel386.h' What compiler should XEmacs be built with? gcc-2.95.2 -g -O99 -mpentium -Wall -Wno-switch Should XEmacs use the GNU version of malloc? yes Should XEmacs use the relocating allocator for buffers? yes What window system should XEmacs use? x11 Where do we find X Windows header files? Where do we find X Windows libraries? /usr/lib Compiling in support for SOCKS. Compiling in support for XPM images. Compiling in support for PNG image handling. Compiling in support for (builtin) GIF image handling. Compiling in support for JPEG image handling. Compiling in support for TIFF image handling. Compiling in support for X-Face message headers. Compiling in support for DBM. Compiling in support for proper session-management. Using Lucid menubars. Using Lucid scrollbars. Using Motif dialog boxes. Compiling in DLL support. movemail will use "dot-locking" for locking mail spool files. Compiling in extra code for debugging. Compiling in code for checking XEmacs memory usage. 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: ---------------------------------------------------------