fixed a series of "next" and "previous" topic links that pointed to the wrong pages.
diff --git a/user_guide/installation/troubleshooting.html b/user_guide/installation/troubleshooting.html
index 27c9c48..62c7548 100644
--- a/user_guide/installation/troubleshooting.html
+++ b/user_guide/installation/troubleshooting.html
@@ -77,7 +77,7 @@
 

 <div id="footer">

 <p>

-Previous Topic:&nbsp;&nbsp;<a href="upgrading.html">Upgrading Instructions</a>

+Previous Topic:&nbsp;&nbsp;<a href="upgrading.html">Upgrading from a Previous Version</a>

 &nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;

 <a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;

 <a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;