We're getting lots of guests spam, which seems completely having no sense, as they do not have hyperlinks put it, and even references to some other recognizable ads are put rarely. For example, one of the recent pieces is "The subject is very good, the building Lord come on".
Does somebody experience the same?

Just because I am being rarely online on weekends, sometimes I miss the time to remove these spam messages, that's why I've come to a very simple solution to enable our boards for registered-members only, but just on weekends, i.e. Saturdays and Sundays.

The code to automate it is quite simple. Under setup_options.php, instead of providing just a definition of $allForumsReg, put the following:

This is an addition to the thread regarding $allForumsReg setting and variations.

Good advice, useful on some occasions. It looks these spam messages appear on different sites (when you put them in "" on search engine). Maybe they 'test the waters' and if they cannot post a link, they still post text. Maybe most of these come from these IPs: dan.me.uk/torlist/ - if so, it might be worth to block them for now..