diff --git a/xpinstall/wizard/unix/src2/nsComponentsDlg.cpp b/xpinstall/wizard/unix/src2/nsComponentsDlg.cpp
index fc7dab1f124d..de4e5419070a 100644
--- a/xpinstall/wizard/unix/src2/nsComponentsDlg.cpp
+++ b/xpinstall/wizard/unix/src2/nsComponentsDlg.cpp
@@ -26,9 +26,11 @@
 #include "nsXInstaller.h"
 #include "check_on.xpm"
 #include "check_off.xpm"
+#include <gdk/gdkkeysyms.h>
 
 static nsSetupType     *sCustomST; // cache a pointer to the custom setup type
 static GtkWidget       *sDescLong;
+static gint             sCurrRowSelected;
 
 nsComponentsDlg::nsComponentsDlg() :
     mMsg0(NULL),
@@ -348,8 +350,13 @@ nsComponentsDlg::Show(int aDirection)
             currComp = currComp->GetNext();
         }
 
+        // by default, first row selected upon Show()
+        sCurrRowSelected = 0; 
+
         gtk_signal_connect(GTK_OBJECT(list), "select_row",
                            GTK_SIGNAL_FUNC(RowSelected), NULL);
+        gtk_signal_connect(GTK_OBJECT(list), "key_press_event",
+                           GTK_SIGNAL_FUNC(KeyPressed), NULL);
         gtk_container_add(GTK_CONTAINER(scrollwin), list);
         gtk_widget_show(list);
         gtk_widget_show(scrollwin);
@@ -468,6 +475,28 @@ nsComponentsDlg::RowSelected(GtkWidget *aWidget, gint aRow, gint aColumn,
 {
     DUMP("RowSelected");
 
+    sCurrRowSelected = aRow;
+
+    // only toggle row selection state for clicks on the row
+    if (aColumn == -1 && !aEvent)
+        return;
+
+    ToggleRowSelection(aWidget, aRow);
+}
+
+void
+nsComponentsDlg::KeyPressed(GtkWidget *aWidget, GdkEventKey *aEvent, 
+                            gpointer aData)
+{
+  DUMP("KeyPressed");
+
+  if (aEvent->keyval == GDK_space)
+      ToggleRowSelection(aWidget, sCurrRowSelected);
+}
+
+void
+nsComponentsDlg::ToggleRowSelection(GtkWidget *aWidget, gint aRow)
+{
     int numRows = 0, currRow = 0;
     GtkStyle *style = NULL;
     GdkBitmap *ch_mask = NULL;
diff --git a/xpinstall/wizard/unix/src2/nsComponentsDlg.h b/xpinstall/wizard/unix/src2/nsComponentsDlg.h
index 077b37653fa9..fcd76d6bd626 100644
--- a/xpinstall/wizard/unix/src2/nsComponentsDlg.h
+++ b/xpinstall/wizard/unix/src2/nsComponentsDlg.h
@@ -50,6 +50,9 @@ public:
     
     static void     RowSelected(GtkWidget *aWidget, gint aRow, gint aColumn,
                                 GdkEventButton *aEvent, gpointer aData);
+    static void     KeyPressed(GtkWidget *aWidget, GdkEventKey *aEvent, 
+                               gpointer aData);
+    static void     ToggleRowSelection(GtkWidget *aEvent, gint aRow);
 
 /*--------------------------------------------------------------------*
  *   INI Properties
diff --git a/xpinstall/wizard/unix/src2/nsWelcomeDlg.cpp b/xpinstall/wizard/unix/src2/nsWelcomeDlg.cpp
index 8519ada15384..69b15ba4c763 100644
--- a/xpinstall/wizard/unix/src2/nsWelcomeDlg.cpp
+++ b/xpinstall/wizard/unix/src2/nsWelcomeDlg.cpp
@@ -176,6 +176,9 @@ nsWelcomeDlg::Show(int aDirection)
     if (gCtx->back)
         gtk_widget_hide(gCtx->back);
 
+    GTK_WIDGET_SET_FLAGS(gCtx->next, GTK_CAN_DEFAULT);
+    gtk_widget_grab_default(gCtx->next);
+
     if (aDirection == nsXInstallerDlg::BACKWARD_MOVE)
     {
         // change the button titles back to Back/Next
diff --git a/xpinstall/wizard/unix/src2/nsXInstaller.cpp b/xpinstall/wizard/unix/src2/nsXInstaller.cpp
index f5aa13eacf1e..a3e5a6eeb2ce 100644
--- a/xpinstall/wizard/unix/src2/nsXInstaller.cpp
+++ b/xpinstall/wizard/unix/src2/nsXInstaller.cpp
@@ -312,6 +312,8 @@ nsXInstaller::DrawNavButtons()
     gtk_container_add(GTK_CONTAINER(gCtx->back), gCtx->backLabel);
     gtk_widget_show(gCtx->nextLabel);
     gtk_widget_show(gCtx->backLabel);
+    GTK_WIDGET_SET_FLAGS(gCtx->next, GTK_CAN_DEFAULT);
+    gtk_widget_grab_default(gCtx->next);
     
     navbtnhbox = gtk_hbox_new(TRUE, 10);
     canvasvbox = gtk_vbox_new(TRUE, 10);
@@ -324,11 +326,11 @@ nsXInstaller::DrawNavButtons()
 
     gtk_table_attach(GTK_TABLE(navbtntable), gCtx->back, 2, 3, 0, 1, 
         static_cast<GtkAttachOptions>(GTK_FILL | GTK_EXPAND),
-               static_cast<GtkAttachOptions>(GTK_FILL | GTK_EXPAND),
+               static_cast<GtkAttachOptions>(GTK_SHRINK),
                5, 5);
     gtk_table_attach(GTK_TABLE(navbtntable), gCtx->next, 3, 4, 0, 1,
         static_cast<GtkAttachOptions>(GTK_FILL | GTK_EXPAND),
-               static_cast<GtkAttachOptions>(GTK_FILL | GTK_EXPAND),
+               static_cast<GtkAttachOptions>(GTK_SHRINK),
                5, 5);
 
     gtk_widget_show(navbtntable); 
@@ -446,6 +448,8 @@ ErrorHandler(int aErr, const char* aErrMsg)
 
     gtk_container_add(GTK_CONTAINER(GTK_DIALOG(sErrDlg)->vbox), label);
     
+    GTK_WIDGET_SET_FLAGS(okButton, GTK_CAN_DEFAULT);
+    gtk_widget_grab_default(okButton);
     gtk_widget_show_all(sErrDlg);
 
     return aErr;