> The first time it receives SIGTERM it says:
> "Exit requested to engine (signal 15)"
> but continues downloading. When giving it a SIGERM
> again it dies with:
> "Program terminated (signal 15)"

> It seems also strange to me that you have to kill it
> twice (via SIGTERM) until it dies.

WinHttrack does the same thing by design. The first press of Cancel allows the
currently downloading files to complete and the cache to be updated properly
before exiting.

If you let it exit after the first signal it might have given a proper status.