Tranfer PC-Laptop problems

[Guest]

For some time I have been able to transfer the outlook.pst file from my
desktop to Laptop so I can work on emails when away from home. The last time
I transferred from the desktop to the laptop I found that I was unable to add
new contacts no matter what I did.
But, when I transferred that same outlook.pst file back to the desktop
everything worked as it should. What is causing this problem?
I am using Outlook 2003 SP2 with Windows XP Pro on both machines.

 

[Guest]

I forgot to add that the Contacts List cannot be found either