I know that stocks below $1.00 can be traded to 4 decimal places, but is that possible for stocks above $1.00? On a list order transactions, one can find prices like $2.2801 despite most ecn brokers forbidding the practice.
It's possible that if someone bought, say, 300 shares, they were able to buy 200 of them at one price, but then had to pay a slightly higher price (say, $0.01 higher) for the next 100. Then the price reported for those shares would be the average amount, and would be fractional.
I'm not sure fennec's answer is the right one.
This happens too frequently to me in thinly traded stocks. I will have a bid of say 2400 shares @ $1.06 outstanding as the listed high bid price and quantity. Suddenly a trade for 200 shares will execute at 1.0601 leaving my offer untouched.
Once in a blue moon is one thing; 25 to 30 percent of the trades and always at $0.0001 above or below my price is another. I suspect someone is "stepping in front" of me. A broker practice forbidden but which seems to happen all too frequently.
For example watch SPPR. Yesterday (10/4/12) at the close, Scottrader listed the high for SPPR as 1.0701 and the low as 1.0699. (Note: Many sites round the data to 0.01; don't be misled.)