Missing classpath entry \your_server_root\was-6.0\properties

[sanjay yadav yadav]

I have installed WAS 6.1 in my system. I want add this in eclipse 3.4. there are only one option version 6.0 to choose.
When I choose IBM WebSphere v6.0 in Eclipse as I try to add a Server Runtine Environment I get "Missing classpath entry \your_server_root\was-6.0\properties" but it does not explain or hint how to resolve the error. Anyone got any ideas - I'd love to hear from you.