It turns out to have been a reiserfs file problem I have a reiserfs filesystem for my home directory. There was some form of corruption in ~/.kde/cache-kanger/http (where kanger is my machine name) such that any file operations on a subdirectory of this caused an immediate machine crash. I eventually had to clear is with a fsck.resierfs --rebuild-tree command -- Alan Chandler http://www.chandlerfamily.org.uk