kill `cat /var/run/TimbuktuHost.pid`(the apostrophes are done with the lower-case tilde (~) key). Note that this will also prevent your computer from being accessed through Timbuktu remotely.
The menu should come back next time you restart the Timbuktu application.
You can also create an Applescript application and put it in Timbuktu's "Startup Items" folder:
tell application "Terminal"[Editor's note: I don't have Timbuktu, so I can't vouch for what this tip may or may not do...]
run
do script with command "kill `cat /var/run/TimbuktuHost.pid`"
end tell

