A few days ago i installed Konqueror on a Ubuntu 64bit machine, upon request.
The installation went smooth (why not?). The issue came up while attempting to get Flash and Java to work.
The workaround was fairly simple.
After installing Java, the trick is done by giving Konqueror the absolute path of the executable:
and set (in my case) to /usr/bin/java
Open a shell window and type:
sudo apt-get install konqueror-nsplugins flashplugin-nonfree
Konqueror -> Settings ->Configure Konqueror -> Plugins.->Scan for new plugins