diff -wruN xdrawchem-1.9.9.orig/xdrawchem/application_ob.cpp xdrawchem-1.9.9/xdrawchem/application_ob.cpp
--- xdrawchem-1.9.9.orig/xdrawchem/application_ob.cpp	2005-11-30 06:47:14.000000000 +0300
+++ xdrawchem-1.9.9/xdrawchem/application_ob.cpp	2011-09-28 05:20:30.750624577 +0400
@@ -87,7 +87,7 @@
   OBFormat *inFormat = NULL;
 
   if (infilter.left(2) == "--") {
-    inFormat = Conv.FormatFromExt(infile);
+    inFormat = Conv.FormatFromExt((const char *)infile);
     if (inFormat == NULL) {
       QMessageBox::warning( 0, tr("Could not determine file type"),
 			    tr("Please select a file type from the list.") );
@@ -187,7 +187,7 @@
   OBFormat *outFormat = NULL;
 
   if (filefilter.left(2) == "--") {
-    outFormat = Conv.FormatFromExt( filefilter.latin1() );
+    outFormat = Conv.FormatFromExt((const char *)filefilter.latin1() );
     if (outFormat == NULL) {
       QMessageBox::warning( 0, tr("Could not determine file type"),
 			    tr("Please select a file type from the list.") );