The Russians have gotten sick of Hugo Chavez's BS and have told him they aren't selling him any submarines at all. Venezuelan negotiators first wanted 9 subs, then they changed their mind and only wanted 6. Recently they were saying "only 3 or 4" and the Russians got tired of the haggling and decided to sell the subs to Viet Nam instead.
It's only in the Spanish language press so far, but he jerked them around. See this account from the Russian news agency Novosti (in Spanish).
We have a happy ending: the Russians are going to sell those submarines to the Vietnamese instead, who will undoubtedly use them to spy on the Chicoms. I can live with that!