Album tracks are in alphabetical order instead of numerical order

Hi

All albums in my music library in itunes, except for
one, display and sync the songs in alphabetical order
instead of song 1-through-end. It's very annoying
having the album played with the songs out of order.

Does anyone know how I can change this and stop it
happening when I add albums in the future?

Thanks

EDIT: Just been messing around in iTunes and it seems
the problem is that the ID3 tag on the albums in the
wrong order don't have the 'track number' field
filled.

From a quick look, almost all my albums I had already
prior to having an iPod don't have the field filled
either. Obviously I don't want to go through changing
them all. Is there a way around this, perhaps by
using the filename of the songs as they have the
corresponding track number?


iPod Nano G2 4gb Red
Windows XP Pro

I just got my 4G Nano and it appears that every tune I add, I will need some sort of ID3 tag. With a few thousand MP3's on my hard drive - most of which are without ID3 tags I was not amused. I am still not sure how things are EXACTLY ordered, but it is at least a direction for me to go in. So online I found a nifty FREE program called Musicbrainz. I am just getting the hang of it, but it appears to recognize my tunes and retag/rename them with some degree of automation. I don't use, and don't WANT to use iTunes to move my music around. But the first step is to get everything that I have tagged. This should also update the track number for you.
I still don't know if the Nano puts things numerically first, and then alphabetically, or by what it sorts it's "SONGS" by. Maybe special character/number/alpha.. but I am working on it. I've asked in a post today for any help in that matter.
Here is the Musicbrainz website: http://musicbrainz.org/