Sorry that I was unclear in my earlier post.
One file I am using that has a large area off the southern coast of California with the problem above (apparent anomalously cold areas that correspond to no-data areas in images produced with 4-pixel sample rate in SeaDAS) is the MODIS AQUA SMI file downloaded from the OceanColor L3 browser is A20081932008200.L3m_8D_SST_4. I am using SeaDAS on a Virtual Machine, but I am more worried about the raw data than the functions of SeaDAS. Since your reply, I opened the BIN file (A20081932008200.L3b_8D_SST.main) for the same data to see if it shows the same anomalously cold areas when viewed in SeaDAS as the SMI file does in ArcMap. It does show cooler areas near zones that have no data for the 8-day composite. Could you direct me to a link that would tell me how to look for errors in the processing of the composites when compared to the L2 files?
The images for all of the files I looked at are below. The second map from the left on the top row is the example from the SMI file listed above.
This image is of the SMI files at a 4-pixel sample rate. I saved the GeoTiff from SeaDAS, and imported it into ArcMap. Note the large black area along southern California.

This image is of the SMI files imported directly into ArcMap with the equation 0.000717*(l3m_data) - 2.0 to convert the raw data to temperature values (and 65535 as NO DATA). Note the cooler areas (more blue) that mirror the black area in the image above.

This image is of the BIN file listed above and produced in SeaDAS. Note the cooler area (darker) that corresponds to the same area off of California. This image is consistent with second image in this post.

By comparing the first two images, you can see that this issue is persistent in these files.