Clicks Vs. Visits & Organic vs. PPC

So I have a problem I just can't figure out (like most of my problems). I started working on search engine optimization for a logistics company about six months ago. They were already running ppc with google and yahoo before I started.

The traffic or "visits" as a result of organic searches or "non-paid" has steadily gone up but at the same time the "paid visits" has steadily gone down at about the same rate. What's weird is the total amount of visits for both paid and non-paid together has remained about the same. Also, the amount of "clicks" in ppc has remained the same and they have been meeting their budget each month.

So could there be some problem with how analytics is attributing visits? Why would ppc visits be decreasing as organic is increasing but the amount of "clicks" over a month remain the same in adwords?

As anyone else experienced anything like this?

I know you said the visits or 'clicks' from ppc have been the same but the prices on each keyword within Adwords (PPC) fluctuates each day/hour/minute. I'm guessing that your PPC keywords are costing you more and your actually getting less clicks before maxing out your budget.

I considered that but the amount of "clicks" indicated in adwords have been about the same each month for the last 5 months. Only the paid visits have been declining each month. So if the clicks are staying about the same each month.....why would the paid visits be declining and clicks remain the same while non-paid increases but I still get about the same monthly total visits for paid and non-paid combined. See data below:

Month/Non-Paid Visits/Paid Visits/PPC Adwords Clicks
March 375/994/1,044
April 279/901/960
May 439/785/859
June 809/694/1035
July 1015/365/943




Here is the difference between "clicks" and "visits" as stated by google:

http://www.google.com/support/analytics/bin/answer.py?hl=en&answer=57164