I assume there aren't any major differences you're aware of between the two setups. ''Is the problem that you sign in, the site behaves like everything is fine, but then when you try to do something, it wants you to sign in again? That could be this:'' Firefox's "Total Cookie Protection" feature limits how sites can use "third party" or "cross-site" cookies, meaning cookies from different websites than the one you see in the address bar. Some sites pass you back and forth between different servers during login because they have their services spread out over a number of different servers. In those cases, you might be able to submit a form successfully on one page and then the next page says you are not logged in. Frustrating! You can make exceptions to this feature when needed (for each server that you visit as part of the process of using this company's services). Try clicking the shield icon at the left end of the address bar (next to the lock). On the drop-down, click the blue slider switch to disable protection. Repeat on the site's other servers as you encounter them. More info in the following articles: * [[Introducing Total Cookie Protection in Standard Mode]] * [[Total Cookie Protection and website breakage FAQ]] Any difference? ''If you are getting a different error message or behavior, could you describe it in more detail?''