these settings affect only 2 things, staying off the EVDO network and making your internet connection
if you are using the mobile web, and need the EVDO, you only have to go back to service menu on the phone and reset the network select to the 'first setting' on the list, digital hybrid mode
the DUN enable and PC settings need NOT be reset, but the same menus used to set them can be used to change them back
although some users have said that doing a calling #228 and choosing option 1 , program phone, has reset their sets to default, but i belive that varies from one phone model to the next