I also had a problem with the QL buttons not working on my HP dv6646 and then when it did start working the orange lights did not work I did the following.
Here is my Quickluanch Solution:
1. go to HP Support & Drivers
2. Enter product number (ex: dv6466)
3. Choose either/or:
» Microsoft Windows Vista
» Microsoft Windows Vista (64-bit)
4. Find HP Quick Launch Buttons driver updates
*** Notice there should be 2 updates (at least for my PC and my friends)
5. Download Oldest Driver First
6. Before Installing Driver , Right Click on it and go to Properties and change compatibility to Windows Vista (SP 2) ... then Install.... Reboot... Test
7. If this does not fix it or works but the buttons don't light orange Download the newer driver listed on the site listed above. Also before Installing change the compatibility again.
I have tried this on multiple HP's and this is the only way I have seen it work if it does work, it only seemed to work when the older driver was installed first and then the newer last.
Note that this will only fix the Quicklaunch and not the Quickplay ... but quickplay sucks so who cares