I just downloaded and applied the Spybot 1.5.2 update, which of course required me to restart the computer. After rebooting I launched Spybot and noticed and a huge difference in the load time. As mentioned prior, the old 1.5.1 version would take up to a minute or even longer for the application to launch from the time you clicked the icon. Now the new 1.5.2 version loaded in a matter of few seconds.
Speaking of load times, I timed how long Firefox took to launch. Much to my surprise it was up and running in about 4 seconds from when I clicked the icon in the Quick Launch Bar. Not bad considering I am using 27 add-ons (25 extensions and 2 themes). I would test how long it would take without SuperFetch, but I don’t quite recall all the steps to disable this feature and from what I recall it is a pain.
I noticed a noticeable slowdown in the overall usage of ff 2.0.0.12.
Based on a thread I found googling I undid the immunizations of that latest spybot (1.5.2).
This turned out to be the problem. The behaviour I expect from FF is back.
I downloaded a great tool call Firefox preloader and it keeps part of Firefox in memory so it loads in like 2 secs.
http://sourceforge.net/projects/ffpreloader/
It works good.