Re:How to update a Tiki install.
I assume that 'German guy' would be myself. Actually I am Belgian, not German. Belgium and Germany do share the same colours in their flags but the direction is different (just like France and the Netherlands).
Updating to Tiki v1.7.1.1 should not be anymore work than dropping in the newest Tiki files in the original tiki directory. But make a backup first! You either overwrite your old files or delete them first. I don't think there are any database changes but you can check if there is a specific SQL update script in the tiki/db directory.
And yes my advice would be to wait for Tiki v1.7.2.
Regards,
Pat.