Forticlient SSL VPN binary not running
Solution 1:
The problem is the same as in the related question, you are running a 64-bit Ubuntu and the fortinet binary is 32-bit. In 11.10 multiarch was introduced which makes it very easy to install 32-bit and 64-bit libraries at the same time, but Ubuntu 10.10 doesn't have multiarch and that's why installing libgtk2.0-0:i386 doesn't work. With older Ubuntu versions some 32-bit libraries are packaged in the ia32-libs package, doing apt-get install ia32-libs will probably solve your problem.
10.10 doesn't have security support anymore by the way, so it might be a good idea to upgrade to 12.04 LTS anyway.
In short:
$ apt-get install ia32-libs
Solution 2:
sudo apt-get install libgtk2.0-0:i386 libsm6:i386 libstdc++6:i386
this will do :)