well i was an ubersocial user but i made the switch to the official rim twitter app.
i didnt like the fact that when i had to tweet a text or a pic, i had to wait for that "bar thing". and yeah it does take a little longer sometimes, as opposed to the twitter for blackberry app which sends it in background (much more convenient for me)
Why don't you try a hard reset or a battery pull. if it still doesn't work then i would suggest to install UberTwitter for your future twitter activities. UberTwitter offers an incredible assortment of awesome options, including retweet-editing capabilities, a cool "nearby" feature, and -- maybe it's just the comic nerd in us -- sweet dialogue bubbles in the Friend Feed. If you don't want to see ads from the Uber sponsors (seeing as free ain't free), make sure you uncheck the "allow sponsored tweets" box during setup.
Isn't UberTwitter the old name for UberSocial? UberTwitter was suspended and they renamed/relaunched under UberSocial.... so UberTwitter is no more.
Unless of course there's another UberTwitter out there.
I've just started using UberSocial myself and still getting the hang of it. I have noticed a slight delay when posting tweets. Haven't tried RIM's Twitter app so can't compare.