Well, I've finally done it
After a frustrating load of crashes and mess-ups on Windows, I decided that I'd be better off moving over to Linux completely. I am now the proud user of Red Hat 9 (old, but good ).
I have transferred all my stuff over with almost no hiccups (with the exception of Thunderbird; see below), and I've got myself sorted out nicely.
Unfortunately, I have to keep Windows installed for gaming: Half Life 2, Raven Shield, and several modding things I do all require Windows .
In transferring my profile data from my Windows installation of Thunderbird to a new Linux one, I found out a few things. Namely, the fact that it doesn't lend itself to hassle-free migration, and the fact that the errors produced are sporadic and random.
I copied over my data folder, and everything was working nicely: Address book, saved mail, extensions; all fine. Unfortunately, I then tried writing a message, and Thunderbird crashed. And crashed. And crashed.
I haven't actually found out the cause of the problem, but I suspect that there's some slight difference in storage format between Windows and Linux, and that messed it up. Or, the data files could've been storing some absolute paths, and they could've messed it up: imagine trying to navigate to D:Program FilesMozillaFirefox in Linux!
What I did to resolve the problem was to create myself an entirely new profile, and just copy my settings, mail, etc. across manually. It was a bit of a gamble, but it paid off, and Thunderbird is now whizzing along doing everything perfectly.