Firefox had been getting slower and slower to start up.  It was getting stupid, 30 seconds, 50 seconds, longer.  If I started Firefox (and made a cup of tea while it was launching), closed it and restarted it, it would only take a few moments, maybe 5-10 seconds.  I turned off Firefox’s check for updates option, maybe it was causing issues, but to no avail.

It was really frustrating.  A search of the web turned up a million posts about Firefox startup being slow but nothing really useful.  One suggestion to turn off session restores, but I was sure this wasn’t an issue with disk writes, it didn’t seem to be doing anything in the seconds it was taking to start, no churning, not much CPU.

I check my add-ons, and I was only running four.  British dictionary, Xmarks, Web Developer and Adblock Plus.  At which point I had some kind of epiphany, and disabled Adblock plus.  Then I went to bed.  No point in just starting Firefox straight away, it was always pretty quick until some period of time had passed, so I figured being asleep should lull it back into a slow start.

Double clicked the icon this morning and 0.5 seconds before I could start browsing.

I’m pretty sure FF3 was slow and not just FF3.5, but maybe it’s worse with Adblock plus and FF3.5.  Maybe I was doing something wrong with Adblock plus in Firefox, who knows.  All I know is that without ABP it now takes under a second to launch Firefox and with it, over 50.

I’m just pleased it’s all working again and I’ll pay the price by manually ignoring adverts (and just hope Firefox avoids issues when adverts from Evil Sources [tm] attempt to install malware by just viewing the ad).