I'm running Avalanche version 1.2.1 (Build 954).
I hovered the mouse over the date range graph at the top of the window, and the earliest bar is showing a range of Dec 29, 2004 - Jan 2 2004:
So first off, those dates are in the wrong order.
And secondly, I sorted all the photos by date, and there are no photos from Dec 29, 2004, nor the 28th or 30th. Nor from those dates in 2003. The tooltip at the other end of the graph says there are 37 photos from Jan 23, 2005 - Jan 27, 2005. I checked, and there aren't any photos from the 23rd, nor the 22nd or 24th. The last 37 photos are all dated Jan 27th 2005.
And thirdly, when I compared the dates in Aperture to the ones in the converted Lightroom catalog, they're all off by six hours.
I'm in the US Central time zone, which is six hours from UTC, so it looks like you're botching the conversion to local time.