Twitter's scaling problems are near-legendary. Ever since it really took off last spring at SXSW, it's been going down for short periods on a near-daily basis. It's a cliché, but Twitter has been straining under the weight of its own success.
This most recent spate of problems has been especially bad, though. I don't know if anything in particular happened to cause it, but the IM functionality and pagination have been disabled for most of the past couple weeks. Read more »