Venture capitalists invested $7.1 billion in 887 deals in the third quarter of this year, according to the latest MoneyTree™ Report, published this past weekend by PricewaterhouseCoopers and National Venture Capital Association, with data from Thomson Financial. The total was down slightly from Q2 2007, which saw $7.2 billion invested in 1,000 deals.

But a contemporaneous report by VentureOne (Dow Jones, Ernst & Young LLP) claims that 635 companies raised $8.07 billion in Q3 2007, for an 8% increase over the same period last year.  “This marked the ninth consecutive quarter of gradual year-over-year growth in dollars invested,” says a Forbes.com report, “and is the highest quarterly investment total since the first quarter of 2001.”

How to explain the discrepancies?  Yesterday, the Wall Street Journal reported the VentureOne data (Dow Jones is its publisher).  The Associate Press reported the MoneyTree/Thomson Financial data, which was picked up by papers across the country, as in this summary by Business Week.  PEWeek Wire, also published by Thomson, promised a breakdown of the data—but so far (as of BVWire press time) hasn’t reported its findings. We’ll keep investigating the variance; in the meantime, feel free to email your insights to the editor.