problem installing postfix

[wade at wadesmart.com]

10202006 0858 GMT-6

When I install anything after my install of 6.06LTS I get a message similar to this message I received when installed postfix:

dpkg: error processing /cdrom//pool/main/p/postfix/postfix_2.2.10-1ubuntu0.1_i386.deb (--unpack): 
 subprocess pre-installation script returned error exit status 1

Every app I try to install wants the cdrom. 

Is this normal now? 

wade