I faced this probs when my account was expired .. on Redhat and CentOS .
I changed my password and now it's working
## Check
# change -l username
# chage -l shirish
Minimum: 0
Maximum: 99999
Warning: 15
Inactive: -1
Last Change: Feb 07, 2012
Password Expires: Never
Password Inactive: Never
Account Expires: Never
OR check shadow file as below if not change
shirish:$1$MpavTBqg$wa827pWNqFMlCDzSx9D.w0:15377:0:99999:15:::
OR you can edit this file by
# chage shirish
Changing the aging information for x82104
Enter the new value, or press ENTER for the default
Minimum Password Age [0]:
Maximum Password Age [0]: 99999
Last Password Change (YYYY-MM-DD) [2012-02-07]:
Password Expiration Warning [15]:
Password Inactive [-1]:
Account Expiration Date (YYYY-MM-DD) [1969-12-31]:
--> Press Enter for default