I installed "fresh" Windows XP, SP 2, latest and greatest mobo, video card, sound card, and directx 9.0c. No mods, scripts, or non-Egosoft content added. No anti-virus or additional processes (outside of win xp services).
The game ran like a top under version ~ 1.2 (whichever came before 1.3). I love strategy and especially realtime strategy, but watching your credits accumulate so you can move the game, technology, and the ability to see other tech and features of the game is like watching grass grow. Not a putdown for X3, I always like to just dive in the first time just to see eye candy, tech, and gameplay. So, I made extensive use of SETA. I left the game running for approx. 24 hours and I had about 4 factories, some 12 transports, and explored only locally (say 4 jumps or less from Argon Prime). I came back, started some sector traders and bought another 6 factories. Probably had about 50+ ships at this point. So, I left the game running another 5 hours. Converted sector traders over to universal and left it in the oven another 12 hours. Awesome!!! I now have about 50 million credits. I decide I must expand my knowledge of the known universe to capitalize on a higher probability of lucritive deals via universal traders. I buy a couple of Nove Vanguards are start bossing around the universe. Let bake another 10 hours or so until I have about 90 million. My rank is not good enough to buy the interesting stuff I want to so I decide to explore even more just to see what is out there. I discover another Argon Shipyard in the Light Heart. So, I start wanting to just mess around, buy a bunch of ships to go looking for a brawl and BAM!!!!! X3 jacks me with a looping freeze move! Just so happens, Egosoft has been hard at work so I pull out a 1.3 patch and fire back!!! BAM!!! X3 strikes back!!! Ok, so I use the MadBoris codec style, only my green codecs of mp3ness and all that are already the best in the known universe.
Suffice to say, my aspirations to conquer the universe with my fully operational deathstar are on hold

What I think can be said from reading related posts and my own experience:
1) This has nothing to do with the latest patch 1.3, if it was introduced, it was done prior to 1.3 and its immediate predecessor.
2) It doesnt matter what hardware, drivers, or codecs you have (although these could cause problems, it will not exempt you)
My Hardware:
CPU: AMD Athlon XP 2500+
MOBO: ASUS a7v400-mx
Memory: 1024 MB
Video: ATI Radeon 9800 ddr 256, then switched with GeForce 6200 ddr
256 after driver clean (also used latest and greatest drivers)
Sound: Sound Blaster Live 24-bit
Description of Crash: Game locks up w/ sound stutter or partial sound loop. Only exits with ctrl+alt+del (sometimes) or complete reboot. No error codes. Except for the one from the CTD when your loading a game, which is unrelated.
WHY THIS POST??? I would like to know what some of your gaming circumstances were and I will give some examples of what I am looking for. I feel this might be helpful to Egosoft. One, if your game runs fine and you havent ran it for more than 24 hours straight and total of more than 48 hours gameplay dont post that you found a solution. I am a serious gamer (as I am sure many X3 players are) and that is not gaming, that is farting around with X3. This crash is random, even my machine (now that the crash has surfaced) will sometimes go several hours before BAM!!!
My observation:
Under a new game, X3 will run fine for hours on end. Once your game progresses to a certain point, the crash will surface. Different actions you take may affect the universe differently, and hence the AI of ships you own ectetera. If Egosoft built in any randomized features into other AI or algorithms, then this could become more difficult to track down. For instance, say it is not the sector you are in, but one that a ship you own is, and it is triggering something. Next time you load, if you took different actions, the ship might make another choice (better deal etc.). Or, if there are randomized algorithms outside of the human element, who knows. I do know however that the crashes surfaced shortly after my universal traders and expansion of knowledge of the universe. Which tells me that it could very likely be the script for the UT, or it could be a sector it is now visiting as a result of my increased exploration. I am absolutely certain that if it were related to hardware or drivers it should have happened long before I reached ~ 100m credits.
How many game hours did you have before your crash?
Did you have universal traders?
Have you visited more than ~30 sectors?
Have you met all of the above criteria, played 48 hours plus, and not experienced this?
Future work:
1) I want to reinstal the game and see if that helps (perhaps it is corrupting itself somehow)
2) Blow away CPU and start over. This time, optimize windows by removing all unecessary services. (I know X3 can be temperamental about such things).