Hi Ian,
thanks for your notice!
Short update about last actions
all changes didn't have any effect

therefore I delete the complete installation. Copy the new version 1.6.1. to the folders and start index.php. (leave the ...config.local... as it was) Now it say: "he, there is a new version, should I do the update?" I confirm with "yes". Afterwards I had to actualize only some plugins and now I'm nearly 90% ready. Need only to add two or three changes, which I 've made in 2007 when I start the blog. And as most usual the documentation was not so perfect, to find it easy

but that's not so difficult than all other before
Resumee: follow instructions in forum/page is better

- first update to actual version!
Anyway, only donwload new version and overwrite the actual installation was not enough, delete, execpt a.m. file, could be the better way.
Thanks for your help!
best regards
Juergen