I have three or four blogs in one host account.
I created a new post, displayed it on Opera browser, saw the update notice for WP, updated it, and now all the posts in that blog have URLs with endlessly redirecting loops in them.
The other blogs in the same hosting account still work fine because I haven't updated my WordPress version yet.
I tried making a test post, and got an error message showing the loop. It had the usual domain/category/upload UPLOAD? This was followed by the whole URL repeated over and over again.
How can I get rid of the endless loop?