Rubles can get a little short in Mafia Wars Moscow it seems. I think that is a good thing though as it makes it more challenging. I liked that fact about Cuba as well. Took a little more planning and thinking to make your $$ stretch farther. The same seems to be true in Moscow. I chugged along fine at the beginning, but now I am into Episode 2 and the rubles are running thin.
One thing you can do to help make up the ruble deficits is to do all your fighting in Moscow and search for people that havent banked their rubles. Seems I can make a tidy amount just from finding the right people to fight.
Grab the Cigarette Smuggling Ring business in Mafia Wars. It yields R$30,000 every three hours making the break even approximately 4 days. After that it is pure profit.
Best of luck in Mafia Wars and happy fighting! Please feel free to leave any other tips in comments.