Why is my Ubuntu desktop panel messing up?

I don’t know anything about the ubuntu panel, but I know some about debugging linux apps, so here we go!

You could try killing off the panel. If you do this command in a terminal
ps -e | grep -i panel
that will list processes with the < ps -e > and parse that list with the < | grep > for the case insensitive word panel with the < -i panel >
Once you find the process, note it’s number, called PID and kill it with
kill -9 PID
Then restart the panel by typing its name, seen from the <ps -e | grep -i panel> command, on the terminal. Should be something like
gnome-panel
And make sure to include a & sign after the end of its name, like this
gnome-panel &
which makes the panel not require the terminal to stay open.

This is jolly good, being about to reboot the panel (hopefully?), but if its still messed up you could try deleting the config files. I don’t know if it will fall back on a default config, or if it will just disappear or crash never to come back…. Anyways, the config files should be in your home directory, in a folder that starts with a period. Open up your home folder and hit Ctrl+h to show hidden folders which only means folders that start with a period. Look for something that says panel. It might be inside a folder that says conf or config. Delete the panel folder and see what happens.

A safer route might be to remove everything from your panel and add items back one at a time, although you’ll need to familiarize yourself with panel customization.

If this is an older computer you might have something vaguely and funkily going on in hardware…

Now that I’ve answered with something poor quality hopefully someone will try to one-up me and help you!