A poll of exit polls show the Socialists gaining 2.5% of votes cast, which would give them precisely zero deputies in the new VR.
Assuming that around 20 million Ukrainians in total voted, if about 100,000 votes for the Socialists could be "found" from somewhere right now, this would give the Socialists 3% of the votes and, bingo! 14 or 15 seats in the new VR, which could significantly tilt the result in PoR's favour.
There are 450 seats in the VR, so each deputy normally is equivalent to 20 million divided by 450 voters, i.e. about 44 thousand voters. But for parties bubbling just below the 3% threshold, a few thousand votes could be very, very valuable.
Update: Both President Yushchenko, in an official statement [in English here] and the Central Election Commission have warned electoral commissions, particularly in southern and eastern oblasts, to make haste and complete their counting of votes. The clear hint is that there may be malevolent intent behind the delay. He added that any falsifications will be dealt with by law enforcement agencies. Hmm..
There is chance that the Socialists may just creep in by a gnat's **** too, so, tension increasing..