Sounds like the steampowered forums's thread blames it on your memory rather than incompetent programming. It's hardly ever your memory. Especially since you're on AT forums, you knew enough to buy decent RAM (not "Generic"). I hope.

For example, I was making my own mod for HL2 (at least trying), and I loaded up the default mod template (HL2DM) in an untouched state. I went to start a server, and noticed the only map listed was "<random>". So I clicked it. And then I got that memory instruction error. It's very obvious that's a result of sketchy programming (on Valve's part). I know it's not my memory. I've never gotten that error with any other program, unless it was frozen or in some odd situation where I forced it to close, etc.
I can't believe people are changing their memory settings in CMOS setup for this problem. I'd like some of what they're smoking. That's sure to complicate the problem even more. If you have bad memory, changing the CAS settings isn't going to do a thing if the chip is bad.
When I had an issue with some "Walmart" (some Generic brand) memory that I had, I got these memory refererence errors incessantly with every program I used. You'd know if your memory was bad, unless just a few bytes of it at the end were corrupt.
Run Memtest86 (at thorough), but don't go further than that. It's Valve's (or ATI's, NVIDIA's, et al.) problem (pretty obvious by the size of that thread), not yours, so don't risk your memory with changing BIOS settings (unless you know what you're doing, of course). I don't want you to learn the hard way. If Memtest86 "passes with flying colors", then there's nothing wrong with your memory, almost certainly.
All that being said I never had this error other than the aforementioned scenario with my untouched "mod". I don't play HL2/CS that much, though. On occasion I'll play Garry's Mod with some friends, which seems incredibly stable.