Virus Protection Software Problem

Do any of you have McAfee virus protection? My McAfee was recently updated, and ever since, I have not been able to register on and then navigate membership websites. I tried to join LiveJournal to read a friends' private blog, but, though my account is set up and confirmed, I can't navigate away from my log-on page. As soon as I click on a link such as "Friends" or "Change Your Options" it brings me back to the log-on screen. I am having the same problem with Evite. I registered and verified the account through the confirmation email. However, whenever I enter my username and password, it brings me right back to the log-on screen. With LiveJournal, at least it acknowledges I'm logged on for one page, if only one page. With Evite, I enter the information, and the screen refreshes with empty boxes for me to enter my info again. I'm thinking that there is some setting on my security software that is doing this, but I can't figure out what it is. Does anyone have any ideas of what could be going on? Is there a setting a need to disable? Does my software have a manic control complex? Does it need talk therapy? Tough love? Grrr...I'm the one who's going to need therapy if I can't get this working...