Slowdown after upgrade to 10.04

After upgrading to Kubuntu 10.04 (Lucid) I noticed high CPU load, high memory usage and heavy disk activity caused by processes called nepomukservices and virtuoso-t. These are used to index files for desktop searching. To disable these go to K-menu -> System Settings -> (tab) Advanced -> Desktop Search -> (tab) Basic Settings and disable Enable Nepomuk Semantic Desktop,

Another program which indexes files is the mlocate package. If you don't use it, remove it.