I used my Pro on my moms computer for a while and now she has purchased it for herself since I use it on my two computers instead. I have tried to register the program into her name, but she gets error messages when she closes the program. Also, it won't let her open a file after she has saved it. This includes ones she has designed. Once she closes the pattern, it disappears forever.
I can email you the two error messages when it closes.
What Operating System is your mother using? It may be a "permissions" problem if she is using Vista and the files are being saved in C:\Program Files\. Try saving them to another folder in that case and see if it helps.