Firefox Takes 52 Bounces to Open - Other Apps Slow, Too

[Metzen]

I have a MacBook with 2 GB RAM, about 6 months old (when I switched from PC to Mac).

Firefox takes 52 bounces to open for the first time after a reboot. Thunderbird and Dreamweaver take 10 each.

Upgrading to Leopard didn't change anything in this regard.

On a PC I would know what to do to clear caches and speed things up, and would eventually reinstall the OS (the only thing you can do on a PC).

What maintenance items should I do on OS X to speed things up again?

Thanks!

[PUNISHER80]

I am also having troubles with the internet, itunes, and my network in general. my pc's do not have trouble connecting through my router so I am 99% sure that the problem is with my Mac and only started after I upgrade to leopard. hopefully someone can help us, cause I too just converted from PC to Mac 2 weeks ago.