Overall great and much easier navigation and usability....Excellent...I am still exploring.
Liked the "My startupnation" link and shortcut area best.....I think it should be placed next to the "log out" area at the top right corner ... (just to group all items that have to do with the members account in one area).
I am not a big fan of the orange gradient header though but i understand you want to have the "sun" effect.... .maybe i don`t like the idea of having SUN`s logo with the white dropshadow...i don`t like dropshadows with logo in general....also the slogan/motto looks a bit dull...i think a white background can make the logo+slogan/motto much more firey and shiny....
The breadcrumb location is great..but i think its width should grow (maybe allow for text wrapping too) to avoid text getting cut....just like for this topic it reads:
"Home > Community > Forums > StartupNation Announcements > New StartupNati..."
I understand your point for this but I think it will look better with the full forum topic title.
The site looks fine of firefox...will try to experiment it on safari and opera as well.
This is my feedback for now...i will post more if i have any more comments...
Excellent work guys...I really love this place 
Riham.