If you use the GUI installer for Sun Management Center 3.5 Update 1 (es-guiinst), the Sun Management Center 3.5 Update 1 Software CD 1 of 2 does not eject.
Workaround: You have several options:
Use the command-line installer (es-inst).
Use a separate CD drive for each CD.
Also, if you are doing multiple installations of the software, copy the CD image onto your hard disk drive and then install from the CD image.