Hi Frank
It looks to me, that you are not installing xowiki as released with OpenACS 5.9.0, but some other version. As you can see in [1], in the version tagged with openacs-5-9-0-final the line 330 starts with the SQL comment marker "--" , whereas in your version, it seems as if lines 329 and 330 are joined together and someone has removed the "--".
Maybe, this is the "customization" you are talking about....
-gn
[1] https://github.com/openacs/xowiki/blob/openacs-5-9-0-final/tcl/xowiki-procs.tcl#L309
