File Share Encryption

I have installed PGP Whole Disk Enryption on my LapTop IBM T400 using Windows XP,
usually asked me every 90 days to change my Admin password, but if I wait for the last days ( less than 5 ) and If I change it,
I can not log again at windows, worst thing I can not pass trouhgt PGP initial step when I restart the computer
so have to ask for a token number to pass the inital step on PGP, after that have to use different tools to change my local Admin password at WindowsXP,

once on windows with the password disabled, I have to uninstall PGP ( wasting time decrypting the whole disk ) , change the windows password, and then install again PGP and a new enryption for the whole disk.

I have seen this behaviour twice.

What Am I doing wrong ?

Are you using PGP's Single Sign On for your disk encryption?  If so, you should be using Ctrl-Alt-Delete to change the password.  If you mistakenly change it without using Ctrl-Alt-Delete, your next boot should require your old password at the PGP prompt for your WDE, and the new password for your User access; but they should then be in synch for the next boot.