I've been using Dreamweaver CS3 and Flash CS3 with no issues on a nearly 6 year-old 1.6GHz Pentium 4 with only 512MB of RAM.
Im running it on all my comps at the moment. I use it most on my HP Laptop P4 2.8 with 2GB of ram. I had 1GB in it before and it ran fine, upgraded since I was always multitasking a lot. I also run it on my little baby sony with a centrino and it's a bit sluggish on that. My desktop of course runs it the best. No real issues with any of them.