Webtrends is the better script. But if you're using different scripts, you'll always seen discrepancies.
For example, AWstats vs Webalizer:
Also, on BlueFind.com we have Webalizer, AWstats, and Urchin, and they aren't even close to each other. Urchin seems to be the most accurate.
Duplicate IP's: 35 (visitors who visited more than once???)
Conversion rate 6.12%
That sounds like the more accurate.