diff --git a/user_guide/general/creating_libraries.html b/user_guide/general/creating_libraries.html
index f17c3cf..6430092 100644
--- a/user_guide/general/creating_libraries.html
+++ b/user_guide/general/creating_libraries.html
@@ -200,7 +200,11 @@
 <br /><br />
 <var>$CI =& get_instance();</var>
 <br /><br />
-<kbd>This is very important.</kbd> Assigning by reference allows you to use the original CodeIgniter object rather than creating a copy of it.</p>
+<kbd>This is very important.</kbd> Assigning by reference allows you to use the original CodeIgniter object rather than creating a copy of it.
+<br /><br />
+<kbd>Also, please note:</kbd> If you are running PHP 4 it's usually best to avoid calling <dfn>get_instance()</dfn>
+from within your class constructors.  PHP 4 has trouble referencing the CI super object within application constructors 
+since objects do not exist until the class is fully instantiated.</p>
 
 
 <h2>Replacing Native Libraries with Your Versions</h2>