Gnome Panel Slow to Appear

I have a single gnome panel at the top of my screen that holds all the applets I need.  It started taking ages to appear (tens of seconds) after logging in.  I tried deleting various applets in the hope that one of them was responsible for the issue but nothing worked.

Some Googling lead me to Bug #593226 in Launchpad.  I opened the Passwords & Encryption tool (in Applications > Accessories) and found that my passwords included two for Desktop Couch.  I deleted both - problem solved.

How to Delete an Invisible Panel Applet

Something went wrong with my Weather Report applet.  It had disappeared from its panel but was still present as it kept displaying a warning message about its inability to connect with the weather server.

I added a second Weather Report applet, configured it and it worked properly.  So, how to delete the faulty one?  I couldn't right-click and remove it as it wasn't visible.

The panel's applets are represented in the file system in

~/.gconf/apps/panel/applets 

and are (usefully) named applet_0, applet_1, ... 

I could have opened each one's XML configuration file and examined it to locate the Weather Report applet but a quicker alternative was to run gconf-editor and examine each applet's configuration directly.

This also gave me the opportunity to compare the configurations of the working and broken Weather Report applets but other than their locations in the panel their configurations were identical.

It turned out that applet_13 was the the malfunctioning one, so I deleted it from ~/.gconf/app/panel/applets.