Hello.
In the Solaris x86 version (VirtualBox-2.0.2-36488-SunOS_x86.tar.gz), VBoxSDL.so is dynamically linked against libSDL-1.2.so.0 which is not included in Solaris 10 (u5).
# ldd VBoxSDL.so
libX11.so => /usr/lib/libX11.so
[ ... ]
VBoxXPCOM.so => /opt/VirtualBox/VBoxXPCOM.so
libSDL-1.2.so.0 => (file not found)
libstdc++.so.6 => /usr/sfw/lib/libstdc++.so.6
[ ... ]
libuutil.so.1 => /lib/libuutil.so.1
libgen.so.1 => /lib/libgen.so.1
#
starting of VBoxSDL will break with:
# ./VBoxSDL
VBoxSDL: supR3HardenedMainGetTrustedMain: dlopen("/opt/VirtualBox/VBoxSDL.so",)
failed: ld.so.1: VBoxSDL: fatal: libSDL-1.2.so.0: open failed: No such file or directory
#
VBoxSDL.so should be statically linked against libSDL.a for the Solaris 10 x86 OS.