According to the BBC, shots were fired near the Georgian leader today.
Georgian President Mikhail Sakaashvili was showing his Polish counterpart Lech Kaczynski the border between Georgia and the "sort of independent" republic of South Ossetia. The shot was heard when the motorcade came within 30m of the border. According to a witness, it was a South Ossetian border guard who fired warning shots.
It is likely that the shots were not aimed at the Sakaashvili, it would have been a total public relation disaster for Russia to accidentally kill Kaczynski. But it is even more likely that the shots were approved by someone high up in the Russian government. Russia might be aggressive but they are not crazy; the last thing they want is some border soldier in the Caucasus starting troubles they did not want. In all likelihood this was a message to Sakaashvili: "If you want to make trouble you better watch your back, and you better not come close to South Ossetia again."