FWIW, I render to an Image Sequence when animating in DS 4.5 and use Vegas (Movie Studio HD 11.0) for editing . It actually works great for me.
Here’s the procedure I follow:
1. Render in D|S to an Image Sequence (I believe you’ve done this already). BTW, I always export in .png format - I’ll address that later.
2. In Vegas, select Import Media from the Project menu.
3. When the Import Media dialog comes up, select Image Sequence at the Files of Type option.
4. Select the first image in the sequence (or the one you’d like your clip to start with).
5. Make sure the Open still image sequence box is checked. Also, verify that the number of frames is accurate to the right of this. If not, or you want to create a clip with only part of the sequence, manually adjust as necessary.
6. Next it will give you a Property dialog. I recommend leaving these all on default setting except for Tape name. Naturally, you should call it whatever makes the most sense to you.
7. Your new clip should now appear in your Project Media pane. You can now drag it down onto your timeline and edit as you would any other clip.
I know it may seem like a bunch of extra steps but that’s mostly because I’ve broken it down so much. Once you’ve done it once or twice you’ll see that it’s really only one extra step in the transfer process that will probably take no more than 20 seconds per clip.
As others have pointed out (several times in several ways), there are many advantages to importing Image Sequences as opposed to D|S created .avi files. But I’ll point out two that I find helpful when using Vegas (they probably apply to other NLE’s as well):
1. I don’t have to deal with .avi’s. Personally, I don’t care for that specific container/format. By importing as an Image Sequence, I can just deal with whatever format (.mp4 in my case) I prefer. This avoids dealing with the less than intuitive codecs included with D|S.
2. Alpha channels are preserved (assuming you don’t export as .jpg or .bmp). I use .png because, IMO, it has the best combo of ease of editing and control of transparency; but you could use .tif if you prefer. Alpha Channels may not be a big deal to you now but having the optional control is always a good thing. Chances are you’ll do something down the road where being able to edit your video in layers will be all but necessary,
BTW, this process should work (with little to no variation) in pretty much any version of Vegas - the person I learned this procedure from was using an old version of Vegas Pro (6 or 7?).
Also, not to rub salt in a wound, but upgrading from Vista to Windows 7 will make your life MUCH easier. Of course, it’s not necessary but then you don’t seem to be happy with Vista, so…
Anyway, I hope that helps.