Sorry, for posting this on blogs.kde.org, but I think it might help a few people out there having the same problem.
So, if you want to get webex working on a 64bit Linux system, basically all you have to do is make sure that all necessary 32bit libraries are present. 64bit firefox with 64bit java are ok.
If somebody knows how to make the Whiteboard feature or video work, let me know. :-)
Hope that helps.