HP recently released version 6.3.4 of its drivers for the HP 6100 All-in-One printer/scanner. After installing the new drivers, the HP Director program will launch on every log-in. To keep the program from launching on every log-in, you can go to System Preferences -> Accounts -> Startup Items and delete it from the log-in list. With an ordinary program, that would be the end of the problem.
However, HP has put in an annoying, hidden program which, if you delete HP Director from your log-in list, will install the HP Director program icon into your Dock on every log-in (without launching the program), even if you don't want it there. If you remove the icon from your Dock, you'll find it re-installed the next time you log in. HP seems to think that they have the right to decide which icons belong in your Dock.
To solve this problem, go to Applications -> Hewlett Packard -> HP Photo and Imaging Software -> HP Photo and Imaging Director and delete the file called "Director Docker." Then, delete the unwanted icon from your Dock and log out. Voila ... next time you log in, your Dock will no longer have an unwelcome icon.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040213172343524