After changing domains, some applications do not work

I've unjoined/joined a user to a new domain.  Nothing was migrated from the old AD - the new domain was installed and users added manually.  
After changing the domain on the client's XP box a new user in Documents and Settings appeared as:
username.DOMAIN
the old username still existed in this directory called:
username

The user is part of the Administrators group on the domain and on the computer.

I copied files from the old username to the username.DOMAIN and most applications worked - except two.  Verizon wireless USB and Palm desktop (calendering, todo's, contacts).  I've uninstalled and installed the Verizon application many times and it works fine when logged in as the administrator account on the domain and as the administrator on the box itself.  However, it throws error "device is busy try again" and will not connect only under the username.DOMAIN account.  The Palm application throws an error about a missing .exe file and does not open at all.  I can open this application using teh Administrator on teh box account and see everything as expected.