I'll preface this by saying that I'm a programmer and web dev myself, so I'm much more lenient when it comes to working with buggy software, as well as far more likely to break out Firebug than the average user.
I looked at connect yesterday and noticed it looked completely different. However it wouldn't show the graphs, said I needed to udpate flash. Went and updated, and they still don't work. I hate flash.
I had the exact same issue, sans needing to update Flash. You need to clear your cache or do a force refresh of the page, Ctrl+R in Firefox, Command-R on OS X for Safari and FF.
Also it won't let me upload my 209 mile ride from the other week; it got an error and now won't let me delete it and locks up the site when I try to view it... still buggy I guess...
Probably a bug with files over a certain size. In the past I have successfully uploaded a 1,400km train trip, but I didn't have second-by-second power data bloating the file size. Definitely something that could slip past unit tests fairly easily; submit a support ticket to Garmin and pray their IT is as good as their warranty department.
I get the distinct impression that GC is meant for the more casual user, especially with the advent of the FR60 and FR110. Garmin knows that the people analyzing every second of their rides are going to be using Golden Cheetah, WKO+, Training Peaks, SportTracks, or some combination thereof and aren't highly interested in pursuing that market.