Am running 6.0.2, when I click on a link, pages are slow or never load.
Ever since upgrading to 6.0.2, I have constant problems with sites loading. For example, msnbc.com, I click on the link and get a blank page with the continuously spinning clockwise arrow. This happens on most links.
A possible cause is security software (firewall) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.
Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.