Strange! Sorry to hear about the (thankfully) transient issue.
In the future, one easier way to check if "it's you" or if it's a Panoramio problem is to open up either a Private Browsing window in Firefox or an Incognito Window in Chrome.
In each case, you'll start a new session on Panoramio (and have to log in), without any pre-existing cookies or (I think) cache to worry about.
If it works in that mode, then you know the issue is with your browser. If things are still broken, then it's likely either an issue with your ISP or with Panoramio.