ok, my next thought would have been a corrupted database structure, although it looks sane to me, but fine that I could help to locate a bug
So, now I can sleep well again, beeing sure it was not me wasting the plugin

Thanks in advance for fixing

mfG
Commander1024

Thanks for the encouragement!

The thrown Warnings are these:
Warning: array_keys() [function.array-keys]: The first argument should be an array in /var/www/blog/plugins/serendipity_event_podcast/serendipity_event_podcast.php on line 166

Warning: implode() [function.implode]: Bad arguments. in ...

hmmmm....

I deleted the podcast plugin in the admin panel and afterwards changed in to the blog-dir to manually delete the remaining folder blog/plugins/serendipity_event_podcast/
Then I used the admin panel to install the plugin via SPARTACUS, with the same error messages as before.
So I deleted ...

Do I have to delete temorary files that are left from the corrupted version of the 0.7 plugin? Because today I tried to update again, and guess what? - it doesn't work!

I also tried to update it manually via the link you provided in your first answer, but all the same.

You might want to have a ...

Oh, alright.
I will retry it the next time I have time tuning my blog. Thanks for the info.

mfG
Commander1024

I think I have found a bug in the serendipity podcasting plug-in.

In stumbled into this error in 2 ways of trying to install the update:

First:
Installed blog version: 1.0
Upgrading the postcasting plugin via Spartacus 0.6 -> 0.7

Second:
Upgrading blog from 1.0 -> 1.0.1
Upgrading the postcasting ...