fnct_ImportDBF uses load_dxf, which is not available if ICONV is not defined.
Similar cases are fnct_ExportDBF, fnct_ImportSHP and fnct_ExportSHP.

I've added at their beginning:

<pre>
ifdef OMIT_ICONV
    sqlite3_result_null(context);
#else<br>
    ... (original code)
#endif
</pre>