Russian officials were delighted that President Boris Yeltsin got through last week's visit to Rome without any of the major gaffes that have become commonplace on his overseas sorties. His hosts were less impressed. Once known for his grasp of complex briefs in high-level negotiations, Yeltsin seemed confused during his meetings, officials said, and reportedly had difficulty telling Italy's Prime Minister, ROMANO PRODI, from the country's President, OSCAR LUIGI SCALFARO. Though he seemed just a little stiff during his very limited public appearances, officials say that in private he walked with difficulty and seemed in danger of losing his balance whenever he had to turn right or left. The unusual measures reportedly taken by his security detail before he arrived in Rome suggested that his handlers are worried about the recurrence of his drinking problem. Before Yeltsin settled into his suite, officials say, his security men went through the place and removed all alcohol.