Login to the forums as usual. With the forums as the active page, right-click its tab and choose Pin Tab. Done. Pinned tabs are similar to any other open tab except for the fact that they are always present when you start the browser and will automatically load the pages that you have pinned. Having these forums pinned in such a manner will preserve your login whether you close the browser or reboot. (When you first open the browser and the page loads, refresh the page with the F5 key or right-click, Reload.) (This doesn't work in Chrome even though it also has Pin Tab functionality.) To undo the pinning, right-click your EQ forum tab and choose Unpin Tab. [Tested with Firefox 26.0]
Yeah i Love it for EQ forums, the log in each visit and no edit always got me the wrong way when they redid the site.