Hi Paul, thanks for the response. My code seems to work ok. At least it seems to be since the array being received and printed to the serial monitor seems to be correct. All the numbers are where they should be.
But I tried your way and that worked too!
Since I am new to this I am going to trust your judgement and stick to your way. Hopefully I will understand it better eventually 
I am working up to filling the arrays with sensor data and definitely need to make sure that the data is being put in the correct position in the array.
hmmm, not sure why thisArray and lastArray are different types. I started with another example that had it that way and just kept it because it worked. Do you see any issues with that? Should they both be byte? int?
I am tracking my progress with my project on my blog. Any comments/ suggestions would be welcome.