Did NASA give wrong size of pixels in microscopic images of MER?

Did NASA give wrong size of pixels in microscopic images of MER?

NASA said Mars Exploration Rovers (MER)
Opportunity and Spirit take microscopic images at 30 microns per pixel.
However, I often found that pixel size was about ten times too large for many fossil cells/tissues discovered in the microscopic images taken by the two MERs. One recent example is Figure 1:
Edit [Moderator]: Link removed
Image source (note 1):
http://marswatch.astro.cornell.edu/pancam_instrument/images/merges/images/1MP962IOF76ORTPOP2957L257F2.jpg
Image Credit: NASA/JPL/Cornell/USGS

In above Figure 1, I marked two complete osteons with Haversian canals, lacunae,etc., but found later they were ten times too large according to the pixel size given by NASA. Another example is
Figure 2: Edit [Moderator]: Link removed

I repeat: this discrepancy with reality has happened since day 1 of MER’s landing on Mars. Something is terribly wrong.

Note 1: NASA recently made public many newly colorized microscopic images taken by MER Opportunity, displayed at http://marswatch.astro.cornell.edu/pancam_instrument/images/merges/merges.html