update sql database with ContentValues and the update-method

I would like to update my SQL lite database with the native update-method of the SQLiteDatabase class of android.

ContentValues dataToInsert = new ContentValues();                          
dataToInsert.put("name", "flo");
dataToInsert.put("location", "flotown");
String where = "id" + "=" + id;
try{    
    db.update(DATABASE_TABLE, dataToInsert, where, null);
}
catch (Exception e){
    String error =  e.getMessage().toString();
}

but I get following error:

android.database.sqlite.SQLiteException: near "15": syntax error: , while compiling: UPDATE mytable SET location=?, name=? WHERE id=2010-09-21 15:05:36.995

I don´t know what should be the problem. Somehow the values do not arrive in the SQL statement. I did nearly the same with the insert method and that worked quite fine.