Problems with Single Sign On

To SAP Portal Support Team.

Dear Sirs:

I need your help with an issue in our SAP Portal. We have configured

Single Sign-On, using the domain user to authenticate the login and it

worked just fine until very recently when it started to behave

erratically, some days authenticating correctly and others prompting the

user for login data.

While trying to solve this problem, I've checked the following:

1. Logon ticket is not expired.

2. SPnego setup is correct.

3. There aren't error alerts in the portal server log.

Please tell me if there are other things that I should check or steps

that I could follow to better understand and/or solve this problem.

Thanks in advance.

Regards,

Priscila Flores