I'm afraid you already solved that, but try to uninstall that module and to reinstall another.
A lot of Slax modules in www.slax.org are not tested - in fact, all modules I've already used have that in top of its description:
Warning: This module is not verified yet and thus it is not recommended to use it. Do not trust it until it is reviewed. That can take several days or even months, so please be patient.
Also, some modules in www.slax.org are require another ones installed to function (see "This module requires" in bottom of each module description).
So try to install modules with all "dependencies together". They normally have "all" in the end of their names and have bigger size.
Try these ones. If they does not function, also download required modules (from bottom to top of list):