libstdc++ library with ifort 10.1

Hello all,

I have a problem compiling a program with ifort 10.1: it seems like I need libstdc++.so.5 shared library, but I only have libstdc++.so.6. And I don't find the previous library anymore...

I found something called compat-libstdc++-33, but not for my distribution Ubuntu 10.04 LTS ...

Is there any way to make it work with library 6 ? Or to install the 5th library ? I am not sure it still exists...

Thanks

Benjamin S.