Mike,
I've not been able to duplicate this myself but a handful of people have had this problem. If you have any insight into possible causes (change in user permissions, crash beforehand - anything) it would be appreciated.
First make a complete backup copy of your Documents/BeerSmith2 directory. This directory contains automatic backup files named Recipe1.bsmx, Recipe2.bsmx, etc... which have complete copies of all of your recipes. So you should be able to open these and then copy/paste the data back into "My Recipes".
You can do the same for Equipment1.bsmx, etc... to restore anything that may have been reset in your equipment, mash or other profiles - they all have automatic backups.
I do apologize for this - as soon as I can determine why this is happening (it appears to be a very rare event) I will correct it.
Brad