Due to a large growth of certain packages, you should not use a CD-ROM to burn the smeserver ISO. You should now use a DVD-ROM or use a Usb Key. (N.B. Technically, you still can burn the smeserver 64 bit ISO to a CD-ROM provided the CD creation software is capable of writing more than the official disk capacity, but not the 32-bit version. Therefore, it is now strongly recommended to use a DVD-ROM or USB Key for both versions.)