diff --git a/Common/IRCDDBGatewayConfig.cpp b/Common/IRCDDBGatewayConfig.cpp
index a84b4ce..e796555 100644
--- a/Common/IRCDDBGatewayConfig.cpp
+++ b/Common/IRCDDBGatewayConfig.cpp
@@ -760,7 +760,7 @@ m_y(DEFAULT_WINDOW_Y)
 	m_config->Read(m_name + KEY_XLX_ENABLED, &m_xlxEnabled, DEFAULT_XLX_ENABLED);
 		
 	m_config->Read(m_name + KEY_XLX_HOSTS_FILE_URL, &m_xlxHostsFileUrl, DEFAULT_XLX_HOSTS_FILE_URL);
-	if(m_xlxEnabled && m_xlxHostsFileUrl.IsEmpty())//To avoid support nightmare, fill the url with the default one when xlx is enabled and the url is left empty
+	if(m_xlxEnabled && m_xlxHostsFileUrl.Trim().IsEmpty())//To avoid support nightmare, fill the url with the default one when xlx is enabled and the url is left empty
 		m_xlxHostsFileUrl = DEFAULT_XLX_HOSTS_FILE_URL;
 
 	m_config->Read(m_name + KEY_STARNET_BAND1, &m_starNet1Band, DEFAULT_STARNET_BAND);
@@ -1434,7 +1434,7 @@ m_y(DEFAULT_WINDOW_Y)
 		} else if (key.IsSameAs(KEY_XLX_ENABLED)) {
 			val.ToLong(&temp1);
 			m_xlxEnabled = temp1 == 1L;
-		} else if (key.IsSameAs(KEY_XLX_HOSTS_FILE_URL) && !val.IsEmpty()) { //always load default url if the value in the config file is empty
+		} else if (key.IsSameAs(KEY_XLX_HOSTS_FILE_URL) && !val.Trim().IsEmpty()) { //always load default url if the value in the config file is empty
 			m_xlxHostsFileUrl = val;
 		} else if (key.IsSameAs(KEY_STARNET_BAND1)) {
 			m_starNet1Band = val;
diff --git a/Common/XLXHostsFileDownloader.cpp b/Common/XLXHostsFileDownloader.cpp
index 438e770..869ddd0 100644
--- a/Common/XLXHostsFileDownloader.cpp
+++ b/Common/XLXHostsFileDownloader.cpp
@@ -66,8 +66,8 @@ wxString CXLXHostsFileDownloader::Download(const wxString & xlxHostsFileURL)
 		return wxEmptyString;
 	}
 	
-	wxInputStream* in = NULL;
-	if((in = http.GetInputStream(path)) && in->IsOk()) {
+	wxInputStream* in = http.GetInputStream(path);
+	if(in != NULL && in->IsOk()) {
 		wxFile file;
 		wxString xlxHostsFileName = wxFileName::CreateTempFileName(_T("XLX_Hosts_"), &file);
 		wxLogMessage(_T("Created temporary file %s"), xlxHostsFileName);
diff --git a/GUICommon/XLXSet.cpp b/GUICommon/XLXSet.cpp
index d1497e1..7d04f98 100644
--- a/GUICommon/XLXSet.cpp
+++ b/GUICommon/XLXSet.cpp
@@ -20,6 +20,8 @@
 #include "XLXSet.h"
 #include "Defs.h"
 
+#include <wx/url.h>
+
 // TODO F4FXL try to figure out why below symbols are not found under ubuntu
 //#include <wx/url.h>
 
@@ -79,13 +81,19 @@ bool CXLXSet::Validate()
 	if (n == wxNOT_FOUND)
 		return false;
 
+#if defined(__WINDOWS__)
 	// TODO F4FXL try to figure out why below symbols are not found under ubuntu
-	/*wxString value = m_xlxHostsFileUrl->GetValue();
+	wxString value = m_xlxHostsFileUrl->GetValue();
 	wxURL url(value);
-	if (url.GetError() != wxURL_NOERR)
-		return false;*/
+	if (url.GetError() == wxURL_NOERR)
+		return true;
 
+	wxMessageDialog dialog(this, _("The XLX host file URL is not valid"), m_title + _(" Error"), wxICON_ERROR);
+	dialog.ShowModal();
+	return false;
+#else
 	return true;
+#endif
 }
 
 
@@ -102,13 +110,16 @@ wxString CXLXSet::getXLXHostsFileUrl() const
 {
 	wxString value = m_xlxHostsFileUrl->GetValue();
 	
-	
+#if defined(__WINDOWS__)
 	// TODO F4FXL try to figure out why below symbols are not found under ubuntu
-	//wxURL url(value);
-	//if (url.GetError() == wxURL_NOERR)
-	//	return value;
-		
+	wxURL url(value);
+	if (url.GetError() == wxURL_NOERR)
+		return value;
+
 	return wxEmptyString;
+#else
+	return value;
+#endif
 }
 
 void CXLXSet::onEnabled(wxCommandEvent &event)
diff --git a/ircDDBGateway/IRCDDBGatewayApp.cpp b/ircDDBGateway/IRCDDBGatewayApp.cpp
index 3b03695..1101563 100644
--- a/ircDDBGateway/IRCDDBGatewayApp.cpp
+++ b/ircDDBGateway/IRCDDBGatewayApp.cpp
@@ -171,8 +171,10 @@ int CIRCDDBGatewayApp::OnExit()
 
 	wxLogInfo(APPLICATION_NAME + wxT(" is exiting"));
 
-	//m_thread->kill();
-	wxGetApp().GetTopWindow()->Close();
+	m_thread->kill();
+	wxWindow * topWin = wxGetApp().GetTopWindow();
+	if (topWin != NULL)
+		topWin->Close();
 
 	delete m_config;