diff --git a/src/ChangeLog b/src/ChangeLog
index cfe1d55e42..889cb344b0 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2006-08-08  Jürgen Spitzmüller  <j.spitzmueller@gmx.de>
+
+	* buffer.C (save): Check if the backup directory is valid and
+	writeable, and warn the user if not (instead of letting boost
+	assert) [bug 2740].
+
 2006-08-08  Georg Baum  <Georg.Baum@post.rwth-aachen.de>
 
         * LaTeX.C (deplog): Add the toc file to the dependencies if a line
diff --git a/src/buffer.C b/src/buffer.C
index 0768c8add2..13648396b9 100644
--- a/src/buffer.C
+++ b/src/buffer.C
@@ -701,7 +701,10 @@ bool Buffer::save() const
 		// good enough. (Lgb)
 		// But to use this we need fs::copy_file to actually do a copy,
 		// even when the target file exists. (Lgb)
-		if (fs::exists(fileName()) && fs::is_writable(fs::path(fileName()).branch_path())) {
+		if (fs::exists(fileName()) 
+		    && fs::is_writable(fs::path(fileName()).branch_path())
+		    && fs::exists(fs::path(s).branch_path()) 
+		    && fs::is_writable(fs::path(s).branch_path())) {
 		  //try {
 		    fs::copy_file(fileName(), s, false);
 		    //}
@@ -709,6 +712,11 @@ bool Buffer::save() const
 		    //lyxerr << "LyX was not able to make backup copy. Beware.\n"
 		    //	   << fe.what() << endl;
 		    //}
+		} else {
+			Alert::error(_("Backup failure"),
+			     bformat(_("LyX was not able to make a backup copy in %1$s.\n"
+				       "Please check if the directory exists and is writeable."),
+				       fs::path(s).branch_path().native_directory_string()));
 		}
 	}
 
diff --git a/status.14x b/status.14x
index 9928f7ee23..d1af6f695e 100644
--- a/status.14x
+++ b/status.14x
@@ -26,6 +26,9 @@ What's new
 
 * Document Input/Output
 
+- Fix crash on save (including dataloss) when the backup directory 
+  was invalid or not writeable(bug 2740).
+
 - Fix crash when importing LaTeX files with no text (bug 2667)
 
 - Ignore definition of lyxgreyout environment when re-importing a LyX