Foren / Cotonti / Support / A variable type check failed, expecting...

So, what I have to do?
The problem is frequent also in list.php and other core modules... also when I navigate the site logged as Admin (so, it isn't a problem related to robots or spiders), in fact, the log, reports I'm causing those bad entries myself...
Moreover, those entries are present in usergallery plugin wich hasn't got $s variable!
For these reasons I was hinking about a bad behaviour of sed_import() function...