diff -Naur --exclude '*~' fityk-0.8.6/src/cli/gnuplot.cpp fityk-0.8.6-fix-format-errors/src/cli/gnuplot.cpp
--- fityk-0.8.6/src/cli/gnuplot.cpp	2008-01-08 14:18:39.000000000 +0100
+++ fityk-0.8.6-fix-format-errors/src/cli/gnuplot.cpp	2009-03-14 12:49:51.000000000 +0100
@@ -111,7 +111,7 @@
     string plot_string = "plot "+ ftk->view.str() 
         + " \'-\' title \"data\", ";
     plot_string += " '-' title \"sum\" with line\n ";
-    fprintf (gnuplot_pipe, plot_string.c_str());
+    fprintf (gnuplot_pipe, "%s", plot_string.c_str());
     if (fflush (gnuplot_pipe) != 0)
         ftk->warn("Flushing pipe program-to-gnuplot failed.");
     bool at_least_one_point = false;
diff -Naur --exclude '*~' fityk-0.8.6/src/wxgui/app.cpp fityk-0.8.6-fix-format-errors/src/wxgui/app.cpp
--- fityk-0.8.6/src/wxgui/app.cpp	2008-03-31 22:05:55.000000000 +0200
+++ fityk-0.8.6-fix-format-errors/src/wxgui/app.cpp	2009-03-14 12:41:44.000000000 +0100
@@ -130,7 +130,7 @@
         return false; //false = exit the application
     }
     else if (cmdLineParser.Found(wxT("V"))) {
-        wxMessageOutput::Get()->Printf(wxT("fityk version ") 
+        wxMessageOutput::Get()->Printf("%s", wxT("fityk version ") 
                                        + pchar2wx(VERSION) + wxT("\n"));
         return false; //false = exit the application
     } //the rest of options will be processed in process_argv()