I think that there is something else in the mix here, Keith.  I believe that you are dealing with a legitimate issue, but if I can't get it to reproduce, then I can't change anything or look at anything.  Changing the description of a column should not have any effect whatsoever on the defaults.  So that being said, I am wondering if there is something else in the mix.  We have made hundreds if not thousands of changes and then redeployed without this specific issue ever coming up.

Now, we are running a more current version which may have inadvertently resolved the issue you are running into.

Do you have a backup that you can revert to and then isolate this in a test environment so that we can see what is happening?

We got around it, Ill try and reproduce in the SF sample database for you.

We have made some changes to the DDT and are planning a build as there are also quite a few new changes including LZMA compression in both the DDT as well as the PackageIt classes.  But this particular issue baffles me a bit as it doesn't make sense.  I believe that it happened, but I just can't see anywhere in the code that this makes sense.  That is why a reproduction would be so helpful.  Glad you got it going.