Comparing a Stock to the S&P - Charts Differ

[JLJ 10]

When I compare a stock to the S&P I get a very different picture when I change the chart to "Dual Axis Charting Mode." I've attached stock charts for MFB, both covering the same time period - the yellow lines show MFB and purple line shows the S&P. In the plain vanilla chart, it appears that MFB consistently out-performed the S&P.

MFB compared to S&P.docx

 

But with Dual Axis Charting Mode turned on (see numbers on left) it now it looks like MFB underperformed the S&P until about August 17 when the lines crossed.

MFB with Dual Axis charting mode.docx

 

How can this be? I understand that sometimes a chart must be compressed to fit the highs and lows of the lines, but that's not the case here.

 

(I'll try to re-do-this post with the proper image uploading technique.)

Edited August 27, 2010 by JLJ
trying to post charts properly and delete my first attempt to avoid cluttering the boards.