I've observed this problem in Ubuntu since I first started with Hoary. I'm now running Dapper. I stopped using Ubuntu's version of Firefox some time ago as a result.
If you want an even faster version than Mozilla's own, try out Swiftfox (getswiftfox.com). There are several versions customized for various architectures. -- Firefox starts very slowly https://launchpad.net/bugs/64844 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs