Interesting discussion! First I think not always you need CSS Grid Framework! Only If you need complex grid or need something fast use some framework.
Someone mentioned Emastic in this discussion, I what to tell you few things about Emastic.
I build Emastic because I needed something small(4 kb) and flexible. If you using Emastic without Plugins shoud be working on almost every modern browser even IE5.5 , 6. With the Plugins you may experience some problems with IE. Put even without Plugins you have (Personalized width px,% or ems, Grid based on ems for better elasticity, fluid columns and other ...). And inside Plugins you have (Grid Based on absolute positioning and Grid Based on %) in the and you have 3 Grid System in one CSS Framework.
Then I stooped and I asked myself why do I need so complex Grid? We don’t build newspaper sites every day. And then I build
http://code.google.com/p/malo/ Malo super small and simple CSS Library(Framework).
My point is if you need some CSS who will handle some complex grid use some Framework otherwise write your own CSS or use some small library like Malo.
I don’t want to make publicity for my projects here, but I will be very happy to here from you! CSS Framework without community is dead Framework.