caribguy - 5:47 pm on Apr 12, 2011 (gmt 0)

Quick checks:

- can your /?p=1234 pages still be found in the index?
- do you use canonical urls to avoid serving duplicate pages
(e.g. /?p=1234&q=aaa != /?p=1234&q=zzz )

Consider rewriting the query string urls to something more intuitive, from /?p=1234&q=aaa to /category/topic

Once you have eliminated these types of technical problems, you'll be able to do a better analysis of your traffic and visitor behavior.