DT Hangs when setting 0 devices

[robochief]

The "Please wait..." windows remains visible, and nothing happens. Can't access the traylist menu, the RAM usage is static.
Killing the process visually eliminates the windows and systray icon, but the process remains visible in the tasks administrator.

I can't reboot, all applications get closed, but system won't restart.

Windows XP Pro SP2 (with all updates)
DAEMON Tools 4.0.3 X86
SPTD1.25

No virus, malware, etc etc. Everything else is clean and working.

[robochief]

I think this happens only after I dismount an image previously mounted, with the extension .img.

Anyone has any clue?