I have a brand new Inspiron 6000 with QuickSet installed and I got the same issue with the FN-F10 key not opening the CD/ROM drive. It appears that Dell has changed their way to manage function keys. Where they used to be managed through the BIOS (such as my old Inspiron 4000), they now are managed through the Windows application QuickSet. However, QuickSet is conflicting with another process "Ati HotKey Poller" which also tries to program the function keys.
I had to disable the ATI HotKey Poller process through the Processes window and that allowed QuickSet to take control of the Function keys. Of course, that is because I do not use the ATI hotkeys functions.