Context: I typically have multiple tabs/instances of Firefox running at the same time; most of these are over plain unencrypted webpages. Often, however, I remember I need to purchase an item, or do some other financial transaction, which involves going to an encrypted webpage. However, for the sake of efficiency, I also often do not close all other browser tabs/windows.
Question: Does this diminish the security I get from my single encrypted tab I've got open? Is there a greater conceptual browser/internet security framework I need to understand here?
(I am running the latest version of Firefox, on Windows XP.)