Session Expiring after 20 mins with Membership API

Hi

We have just implemented the Membership API. It seems to be working great, however the users logged session times out after 20 minutes. I know the standard session time is 20 minutes so it looks like we have a problem with either the "keep me logged in" setting or an issue with the cookie itself.

I have compared the cookies to our previous system and they seem identical (and in the same format as the cookies on this site) - eg with 1 year expiry.

We have the this setting as per: Const blnMemberAPIautoLoginCookie = True

I note our cookie domain for the WWF cookies is being set as: .domain.com (with a preceeding ".") and we have the path set as "/". (these are the same settings as the old server)

We're running 11.0, previously running 10.17. I have compared the code for the API and the various function calls and cannot see any differences that we have not merged.

Obviously I am missing something (and we have a lot of annoyed users) - any insight you can provide me would be very helpful.

Thanks in advance.

Craig