Commerce portal 3.70 - IE not refreshing session data

Hi all

This is a new one to me after 6+ years of using commerce portal.

Customers logging in to the e-commerce site are not seeing the login bar refreshed to show their ‘logged in’ links, i.e. my account, order form, etc. Instead, the login and password boxes stay there just as if they have not logged on. Doing a forced refresh of the frame on Internet Explorer correctly refreshes the data. The same applies if they log out, the browser does not go back to the ‘login’ screen, they still see the things they normally see when logged in.
Closing the browser and re-opening it, and even restarting the webserver does not fix the problem, the customers go back in to the site and are already logged in.

So far, a couple of customers have reported this in the last few days. For the first customer, I assumed it was just a browser issue, but now we have had 2 reports, I’m wondering if it’s something else. The first customer I spoke to also had Firefox, and that did not display the same symptoms!

Any ideas appreciated