I am writing this response for the original poster as much as for myself to help get this straight in my head, so please bear with me.
I consider myself a very novice user, but a quick search on google brought up a nice FAQ about this...
http://xdvfaq.tripod.com/#4.12. I found it to be very descriptive. For the click impaired here is my take:
There are 2 types of color
You have Video color and Computer color:
Video color White to Black is 16-235 (601)
Computer color White to Black is 0-255 (RGB)
When you import with Avid you tell it what your source is by selecting 601 or RBG.
If you specify the source as RGB it will push the Whites and Blacks together to fit into the 16-235 range for video use
If you specify the source as 601 it will leave your colors alone (because it expects them to be already in the 16-235 range).
That's my take, but read the linked material and compare.
If I understand it correctly,
Bars already in the 601 colorspace should be imported 601 to avoid Avid "Crushing" the colors
Bars in the RGB (standard graphics editing output) colorspace should be imported RGB so Avid can put the 0 whites and 255 blacks into the 16-235 range.
Does that sound right?
