Warnings and info messages on my index page

[Zugschlus]

It doesn't offer to update the spamblock plugin, thogh.

No it does not, while spamblock is a core plugin shipped within releases and its last version is 1.77.
Whats your version number?

I have 1.71, and that does not even update when I remove and re-install the plugin from the admin frontend.

Pretty radical method, remove serendipity_event_spamblock directory and svn update again. Now at 1.77, and the messages are gone.

Thanks for helping.

Greetings
Marc