Firefox odd behavior

[Arlos]

OK, I suspect I may just be missing a setting somewhere, but on my laptop, Firefox always starts up again in the exact previous state it was when it was previously shut down. Same tabs, same websites, even the same history in the forward and back buttons. This is not how I want it to behave. What I want is for it to come up with my default home page on the default tab. (my default home page is about:blank)

In Tools | Options | General options, my home page is indeed set to about:blank. Note that this is only occuring on my laptop. The firefox on my home machine (where I don't remember turning any option like this off) works just like I want it to.

Any ideas?

-Arlos