I have a 32 bit system (which means only 3.5 g max on the OS and 2 g max on any one application. My last render had Stoemason's Tin pan alley, another low-resolution building set and about 7 or so Poser figures. Here's a few tricks that might help:

1. Purge, purge, purge. There is a "purge memory" button (at least in Vue Infinite). I use it everytime after opening a file and again everytime I load an object, if the application is slowing down.
2. Save frequently. When I'm working on a scene I usually have two or three differently named files to go back to if something goes bad.
3. When I use Poser imports, I first import them into the default scene that Vue opens with. Then I retexture as necessary. Then I save the figure as a .vob file. When I'm ready for it, I just load it into the scene. This seem to help dramatically, as Poser files seem to suck up resources. You can also resample the Poser texture maps at a smaller size, although I've never had to do that myself.
4. You can change the look of your views. Instead of using shaded figures, try wireframe figures.

As far as ATI cards go, I started years ago with a free version of Vue 3.5, got 5 inf,, 6 inf. and just upgraded to Vue 8 Inf. During that time I've used:
9700 pro
9800xt
850xt PE
1950xt
4870
5870
So far, up to Vue 6 I've had one graphics related issue that involved one specific driver. Vue 8 is giving me a bit of a slow response (at least with the one render I've worked on so far). However considering that -a) It's originally a Vue 6 file, so it could be simply an import issue.
b) I'm still using XP pro 32 bit. Not only am I limited by the 2G address limitation, but also by older software.
c) it's a relatively new card and I haven't gotten around to updating drivers yet.- I really can't complain.
As far as Vue issues go, I agree with Rutra. You have to spend some time optimizing your computer. While I don't have a computer dedicated to CG, I placed a shortcut on my quicklaunch bar to disable my internet connection and I have anitvirus software that can be disabled. When I'm working in any graphics program, my internet and my antivirus are turned off. My system visual effects are set up as"adjust windows for maximum performance." I'm also pretty fanatical about crap that runs in the background unnecessarily. My systems tray has nothing outside of my time/ date icons except my antivirus - and that's off when I'm working on CG. If you take a quick peek at my gallery, you'll see I use a whole heck of a lot of poser imports in my renders and I rarely, if ever have major issues. And anybody whose uses the Vue/Poser combination can tell you that poser imports are resource pigs. And with one exception, I've used whatever gianormous texture maps that Poser used, rather than reducing the file size as is usually done.

Awesome! I seem to have that problem frequently, especially with spotlights. In the past, I set up a light for close objects, then maybe a few more for further objects and adjusted the influence accordingly. Obviously this is not the most realistic, or resource friendly method.
 Your method is much better.
Thanks a million, that's a great tip!
 Gary

That was a great tutorial! I do have one question, though. When you adjusted the light settings, rather than turn down the power, you modified the filter. Does that have a different result than just lowering the power?

Actually, with fluorescent lights, it depends on  the type of bulb. 4000k tend to look slightly bluish, whereas the 3000k-sih bulbs almost appear pinkish. Mercury vapor lamps, such as most streetlamps, have an orange cast to them.