I have this problem found here: http://modthesims.info/wiki.php?title=Game_Help:CAS
I thought it was just cas, but the mirror lags as well and the hair works fine. I was wondering if a fix was ever found.

The mirror and CAS use similar code to achieve their similar effects, so a problem in one is likely to be a problem in the other.
I have generally found CAS (including clothing) to run much more slowly when I've recently added a lot of custom content, or for some reason have deleted the CAS thumbnails. This is because the game doesn't create thumbnails until an item is called up. There isn't anything to be done about this, and unless you delete thumbnails frequently it should only be an occasional problem.

If your makeup is lagging consistently, the most likely thing is that you have something in your makeup that the game is having trouble handling. I would suggest taking a look at your makeup subfolder (if you don't have your makeup all together in one subfolder this is going to be much harder!). How big is it? Did you add anything shortly before the problem started? Have you got a lot of files with nonstandard characters in their names - things like [ ( & + etc. - that the game can't read but will spend some time trying anyhow? Take out the recent additions and rename the files with nonstandard characters and see if the problem persists.

If it does, it's time to knuckle down to troubleshooting. If you temporarily rename your TheSims2 file and launch the game to create a new one, you can make a new Downloads folder containing only your makeup files without disturbing any of your games. Do CAS and the mirrors still lag after you've given the thumbnails a chance to generate? If so, the problem is definitely in your makeup downloads, and you should be able to test for which ones are guilty fairly quickly in this environment, as the game will take very little time to load. A standard 50/50 (as described in the game help FAQ you were directed to before you were allowed to make this thread) should be doable in under an hour, on most systems.

It has always been lagging as long as I can remember and I it's not just make up it does it to eyebrows, face paint, and accessories. All my make up, accessories, ect all the thumbnails are loaded.I also don't have any special characters since I renamed them. I not sure how much make up and ect I got since I keep it in a folder with my skins and eyes, but I'm guessing it's probably around about 2000 or less if I exclude eyes and skins. I have way more clothes,hair, and objects, but I experienced no lag when I go through them. I'm not sure if it has anything to do with apartment life, since I had hardly any lag, but I had less make up and ect.
I forgot to mention that it is slow when I go through them, but it is bearable it's the make up and accessories that take a while to put on a character and the eyebrows are slightly better, but there is a bit of drag. It's also really drags if I turn the character around or in cas when I click the number 4 it slows down to go to the characters face.

This is a really common problem. If you have a lot of custom makeup, face paint, accessories, etc. it'll lag when opening that part of CAS/the mirror. I have tons of clothes and hair and its laggy for me when I open the clothing and hair customization menus too. Really, the only way I think to cut down on the lag is to go through your CC and clean out files you don't particularly care for or use.

I was thinking I probably have too much make up and I thought it was weird that I don't experienced any lag when I go through my hair or clothes, since I have way more files. I thought it could be fix since the wiki page mentions that the problem started in the later expansion packs. Thanks.