No such problem here (tested under a native Windows 7 64 bits session with voice enabled).
Without the logs, I can't say what went wrong on
your system, but you seem to be the
only person with such problems, and I already pin-pointed
here something that was very wrong: do not bother reporting more
apparent bugs till you got this issue fixed (again, virus and anti-virus software are the usual suspects). Also you said that you were using only one core for the Cool VL Viewer: it should work just fine with all cores enabled; if it does not, it's another proof that there is something
seriously wrong with your system. Again, it's useless to search further till you got that other issue fixed as well.
My advice is: try installing Windows 7 (the genuine one: not a pirated copy !) on another partition of your hard drive, then test the Cool VL Viewer under it just after the installation is done (and before adding any other software, especially antivirus and pirated software that can bear viruses).