More gas problems for Europe could be on the way with a warning from Russia’s prime minister that Ukraine may have difficulties paying its bills.Ukraine is in the midst of a vital presidential election but Vladimir Putin said Ukraine’s president Viktor Yushchenko was hindering the central bank’s use of gold currency reserves. Ukraine’s central bank insists it has enough dollars. “It looks as though we will again have problems with energy payments, which is very sad. The IMF made a statement yesterday and, if I am not mistaken another today, saying the Ukrainian authorities are carrying out ruinous economic policies. If it continues, the IMF refuses to cooperate with Ukraine,” Putin said. Last winter, gas for Europe only seeped through Ukraine while Kiev and Moscow were engaged in a bitter dispute over prices, share of supply and transit revenues. Russia supplies the EU with a quarter of its gas, and most of it arrives via Ukraine.