MySQL 3.24?
 

Load http://www.pixelpost.org/, click on the requirements and among other thing this shows up: "MySQL 3.24 or greater". I was quite surprised because I have never heard (neither google) about any MySQL 3.24.X release. Am I wrong?

It may be a typo, or someone rounded up, or something else.

PP supports version 3.23.58 and up.

Probably typo as software versions aren't usually rounded :D

True, but it wouldn't have worked to just put 3.23, since it won't work with earlier releases in the 3.23.x line (like .10 or .53).

So there should be 3.23.58 or 4.0 but not nonexistent version - it's very confusing.

Yeah, it's definitely something that should be fixed. The documentation has the minimum requirement listed as 3.24.58 or higher.
http://www.pixelpost.org/docs/GettingStarted/Install

Seems to be fixed.