Steve,
I have the same issue where my LEM appliance (virtual machine) is unable to mount windows shares when trying to upgrade through the console (same error 13). If you contact SW support they can provide your root credentials and once under root you can try manually mounting the share. I was finally able to get mine to manually mount using the below command:
mount.cifs //host/LEM /mnt/share -o username=someuser,sec=ntlmssp
I used a local account and had to specify the security mode to "NTLMSSP" which overrides the default of NTLM that cifs-utils version 4.5 uses (which is what my LEM appliance has installed).
Once I was able to mount the share SW support provided me with a work around to modify the upgrade script and copy the TriGeo+Upgrade directories to the cdrom mount location and then I successfully upgraded through the console choosing the CD option. It would be nice to have more customization options for the Upgrade portion of the console.