I downloaded the sources and image from:
http://squeakvm.org/squeak64/dist3/

Then I compiled with make WIDTH=64. A few steps later:

timmy at timmy-desktop:~/src/squeak/seaside-test$ squeak
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
X error
...


ldd /usr/local/lib/squeak/3.8a-2/vm-display-X11
        libGL.so.1 => /usr/lib/libGL.so.1 (0x00002b37236d5000)
        libXext.so.6 => /usr/lib/libXext.so.6 (0x00002b3723892000)
        libSM.so.6 => /usr/lib/libSM.so.6 (0x00002b3723aa4000)
        libICE.so.6 => /usr/lib/libICE.so.6 (0x00002b3723cae000)
        libdl.so.2 => /lib/libdl.so.2 (0x00002b3723ec9000)
        libm.so.6 => /lib/libm.so.6 (0x00002b37240ce000)
        libnsl.so.1 => /lib/libnsl.so.1 (0x00002b3724350000)
        libX11.so.6 => /usr/lib/libX11.so.6 (0x00002b3724568000)
        libc.so.6 => /lib/libc.so.6 (0x00002b3724876000)
        libGLcore.so.1 => /usr/lib/libGLcore.so.1 (0x00002b3724bc7000)
        libnvidia-tls.so.1 => /usr/lib/tls/libnvidia-tls.so.1 (0x00002b37254fb000)
        libXau.so.6 => /usr/lib/libXau.so.6 (0x00002b37255fd000)
        /lib64/ld-linux-x86-64.so.2 (0x0000555555554000)
        libXdmcp.so.6 => /usr/lib/libXdmcp.so.6 (0x00002b37257ff000)

ldd /usr/local/bin/squeak 
        libutil.so.1 => /lib/libutil.so.1 (0x00002b0ea60df000)
        libdl.so.2 => /lib/libdl.so.2 (0x00002b0ea62e2000)
        libm.so.6 => /lib/libm.so.6 (0x00002b0ea64e6000)
        libnsl.so.1 => /lib/libnsl.so.1 (0x00002b0ea6768000)
        libc.so.6 => /lib/libc.so.6 (0x00002b0ea6981000)
        /lib64/ld-linux-x86-64.so.2 (0x00002b0ea5ec2000)


It seems to work if I use the null display device. What should I do?
Thanks.