Hey, just wanted to say thanks for the plugin.
I purchased the VFD Model HY02D223B from cnc4you.co.uk and this USB adapter -
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=331099811041&ssPageName=ADME:X:RTQ:GB:1123 and although I needed to load the CH340 driver not the prolific one everything just worked.
I've even kept the old relay control that used to run my router to start and stop the water cooling pump for the spindle.
I've not had any noise issues yet, but my stepper motors all have ferrite clips, and when they arrive I'll be adding some more to the VFD/Spindle and the cable between the PC and the VFD just in case.
Just for info, I'm running this on XP with a 1.8ghz CPU and 512mb ram. The Mach3 is the current version 3.043.062 and I just followed your excellent instructions.