Description of Problem:
After completing the TUI "Firewall Configuration - Customize" screen, if
you choose Back and later reenter it, the "Other ports" field is preserved
but the checkboxes (DHCP, SSH, Telnet, etc.) are not--they're all blank.
This could easily lead to a failure of expectation that the values were
preserved, so the user thinks they don't need to revisit the "Customize"
screen the second time through.

How Reproducible:
Always.

Steps to Reproduce:
1. Enter values on the "Hostname Configuration" TUI screen.
2. On the next "Firewall Configuration" screen, choose the "Medium" radio
button, and then click the "Customize" button.
3. Select several checkboxes (I did SSH and WWW), and also enter an "Other
ports" value (I did "finger:tcp,auth:tcp"), and click Ok.
4. Click Back. (This is the important part... revisiting Customize
without Back won't reproduce it.)
5. Click Ok on the "Hostname Configuration" screen.
6. Click Customize on the "Firewall Configuration" screen.

Actual Results:
The checkboxes set in step #3 are now blank, although the "Other ports"
setting survived.

Expected Results:
The checkbox values previously set should be preserved.