When I am logged into stackexchange.com, I try clicking on my name at the top bar and I'm taken to a page that directs me to where I might find pandas (Page Not Found) (link). As a side note, I look to the right of my screen and alas there are no pandas there. Anyway, is clicking on my name supposed to be taking me somewhere else? I can access my SO profile just fine from stackoverflow.com.
This was a tad subtle.
Basically, sometime in the last week or two your "identity" changed from the Stack Exchange network's perspective.
Why you ask? Probably because of an OpenId change (I see a number in your recent user history) that led to us picking up an older account in your associated accounts.
StackExchange.com ties your identity there to your identity on the oldest account you own. If the apparent oldest account changes, things can get a bit... odd. Throw in some caching, and now you're getting directed to a page that doesn't exist anymore.
Anyway, this should now be resolved; the link on StackExchange.com will take you to a page that actually exists.