SSO login.ticket_lifetime value...Please guide

Hello All,

Am working on ESS/MSS and facing an issue with SSO

Only one user is getting an error saying "RFC_ERROR_LOGON_FAILURE_System received an expired SSO ticket".

I have gone through almost all the relevant SAP Notes & previous SDN posts and have following questions:

1. Default value is 8. Are there any implications if I change this to 100?

2. I do understand that this error is related to JCo but then why is this only to one user?

3. In my scenario wherein a couple of test userids are being shared amongst the consultants here...what is the value thats recommmended..

Awaiting Reply.

Thanks and Warm Regards,

Ritu