Thanks for your post!
Each build that you create via SmartAssembly gets a new 'AssemblyID' added to the 'Builds' table of the SmartAssembly database. And if error reporting has been applied to the build, a map file is also created for it in the maps folder, named with its 'AssemblyID' value.
It could be a lengthy (and risky) process, but you can look through the database--if you're confident you've found the appropriate ProjectID and AssemblyID of your specific version, you can look for all the other AssemblyID values created for the same ProjectID and delete any mapfiles with the same name.
If you go ahead with this, kindly make sure to backup your map files somewhere first! If any needed map files are accidentally deleted, you may not be able to receive/read incoming error reports anymore.
(If you have any further questions on this or accessing the SmartAssembly database in general, please let me know!)
Red Gate Software Ltd.