Rails - Nov 2006 - migrations gotcha

Just wanted to share this gotcha:

   1. Create model A and initialize some record from
      within the very migration.
   2. Create model B (perhaps 27 migrations later,
      two weeks later).
   3. An observer of A uses B.

Now you can''t do a fresh install (or go down to VERSION corresponding  
to 1. and then up).

-- fxn