Ubuntu – missing libraries in ubuntu 11.10 – used to work perfect in ubuntu 11.04

I'm trying to install the Aventail tunnel client to connect to my workplace server. I'm getting the following error when I run the installer script:

Using certificates in /etc/ssl/certs
One or more dependencies cannot be resolved.
Aventail Connect install failed.
To uninstall, run /usr/local/Aventail/uninstall.sh

Error details:
linux-gate.so.1 =>  (0x0049e000)
libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0x00a40000)
libssl.so.0.9.7 => not found
libcrypto.so.0.9.7 => not found
librt.so.1 => /lib/i386-linux-gnu/librt.so.1 (0x00c41000)
libstdc++.so.6 => /usr/lib/i386-linux-gnu/libstdc++.so.6 (0x00110000)
libm.so.6 => /lib/i386-linux-gnu/libm.so.6 (0x00e8f000)
libgcc_s.so.1 => /lib/i386-linux-gnu/libgcc_s.so.1 (0x0074b000)
    libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0x00a93000)
    /lib/ld-linux.so.2 (0x00257000)
>> 

I'm trying to install all missing libraries, but to no avail. For example, if I do:

sudo aptitude install libssl-dev

I get the same result.

What does this means?

I'm seriusly -SERIUSLY- beggining to considering leaving ubuntu and going back to slackware. I've lost about a week's work. First I had to reinstall the system after an upgrade, unluckly decided to install the newest version, and now I cannot even connect to the server. And I'm not speaking about the changes in the window manager.

Seriously, the new nice window manager is great for my wife and son. But for enterprise things, to change constantly is not good. Just a comment from a long time linux user.