I have added the RSS1 widget for twitter to my blog, but all it shows is an error message… “An error has occurred; the feed is probably down. Try again later.” I’ve checked twitter and all is well there.
I guess it was having trouble pulling the feed. I guess I would suggest trying it again as it didn’t say it wasn’t a valid feed at least. Maybe clear out the feed address and save it and then go back in and try adding the RSS url again.
When I tried it, the RSS button pointed to friends_timeline, instead of user_timeline. Since I had no Twitter friends at that time, it threw the error message you mentioned. Changing the url fixed the problem.