You might want to take a look at Dugan Chen's
Optimizing Slackware Linux’s Fonts at
http://duganchen.ca/writings/slackware/fonts (in case you haven't already done that) just to make sure you've got things set properly. It may be as simple as following his configuration guide for Unicode/UTF-8 (that would be my bet).
It may also be your keyboard either not being recognized or incorrectly recognized and you may want to look into that setting as well.
Hope this helps some.