It seems like I wasn’t that stupid after all:
Thanks to Eirikso for catching a mistake in the new install instructions for Bot-Check in WordPress 1.5. The old instructions have you remove an if statment that checks for a logged in user. A new download has been put up with correct install instructions.
To fix:
Add
Right before the line
Logged in as …
So, now I am up and running with the latest version of BotCheck and can recommend this little plugin for everyone running WordPress 1.5!
Related post:
BotCheck for WordPress 1.5
eirikso 
And with that fix, I also installed the plugin. Definatly a “must have” if you blog with WP 5.1
Wonder if Brian has _any_ reports on people getting comment spam after installing this plugin?
[…] Thanks to a Eirik, I’ve also installed the brilliant plugin to prevent comment-spam: Bot Check. I used some other tool on my previous WP-blog, but this one is very easy to setup, and works great. A “Must have”. Thanks to Eirik for sharing, and to Brian for making […]