Over a period of time SPE was not able to clear the temp files that were dumped to disk file during scanning.
If LU is triggered during load condition, file handles for temporary file(s) get inherited to child SymcMicrodefsManager process, which prevents Decomposer from closing nor deleting them.
Please be noted that this issue is applicable to only Windows platform.
Now new functionality is added so that child process will not inherit open files even though LU is triggered.
You can achive this by applying attached hotfix.