As a work related issue I have kept an eye out for information on this problem, and can now report a couple of findings.
Firstly, not all converters are capable of generating an RS232 break. This is not required for Megajolt, but it does affect some applications.
Secondly Windows treats all converters interchangeably and will only <b>ever</b> install one driver. This means that if you ever use more than one type of converter the chances are that Windows will use the wrong driver. I suspect that once you have got into this state you will have to uninstall the driver and then re-install the correct driver to force Windows into using the correct one.
Newer is not always better
