I am using a nested model to merge a large number of Shapefiles, then dissolving them based on a specific attribute. The solution to this was outlined in another question (Dissolving shapefile but retain attribute fields using ArcGIS Desktop?). But if I use the option to store the Merge result as a scratch file, all my fields but one are not in that file, so my end result when I try to spatially join the Merge result to get my fields back is that - of course - they aren't there. But, if I specify a permanent Shapefile for the Merge step, and use that as my input to the Dissolve step, all my original fields are there in my final result. Is there some step I am missing or is there a bug in the use of a scratch file for my Merge step?