Based on a search of the Worldsims forums, which you may want to do yourself, it looks like you've got a graphic card driver problem. That's usually what is mentioned as a problem with flashing red walls. First be sure you've got all the necessary patches from the official site. Then check out this thread: http://forums.worldsims.org/showthread.php?t=2874 for information on updating your drivers.
See, I'm having that problem too. Unfortunately, I have an SiS Manufacturer... and I have no idea what that means. It's not intel, or the others mentioned. And I'm not sure where to find the patches... xP I am so computer-challenged, it's not even funny. Would you mind linking it?
The patches are on the official game site, under the Help section: http://thesims2.ea.com/update/?pid=Help_patches As for your graphics card, I'm computer challenged, too, when it comes to the technical. I knew only enough to show you where the helpful thread could be found in Worldsims. I believe there are other discussions about it. Use the search function at the top of the page. Here's another one, for example, under the FAQ at the top of this page: http://forums.worldsims.net/showpost.php?p=94501&postcount=4
SiS cards are old, don't have TnL and they are not supported by the game. In fact I'm surprised it even ran TS2 with these problems, you need to buy a video card.
