libstdc++.so.5 has been removed in Ubuntu Karmic.
This should help you:
Missing libstdc++.so.5 in Ubuntu 9.10 (Karmic)
I wanted to install the final Catalyst 9.10 on Ubuntu Karmic, and I get this error thay says:
libamdxvba1 depends on libstdc++5
So I proceeded without installing libamdxvba1. What problems could I have by not installing libamdxvba1?