background.exe used in Windows CFASTbot fails with -u

[rpeacoc]

When running CFAST cases, CFASTBot for windows uses background.exe (from SMV repo) to runs multiple cases at a time. By default, it uses options -u 85 -d 0.01. With the -u option, the scrip simply stops when attempting to run the first case.

The -U option with background.exe works fine.