This may sound illogical -- It certainly does to me, as I do not see why Mach3 would appear to have some effect on hardware, but I had a similar experience with a laptop.
When I installed the license, Mach3 started reporting "external E-Stop requests".
Nothing had changed other than installing the license.
Some of the details are below, but based on conventional wisdom that laptops are not good platforms for the parallel port driver, I replaced the PC and have had no problems since.
The Mach3 licensing process may be having some effect on the parallel port driver that is causing marginal pp cards to no longer work.
Graham
Details:
I ran Mach3 for several weeks in unlicensed mode with the pp driver installed with no issues.
My configuration was as follows:
IBM ThinkPad Onboard parallel port
Win XP service pack 3 (a customized install, with no extra drivers, services, bloatware, etc.
Gecko G540 - Charge pump enabled, EStop connected
Mach3.043.066 - Charge pump on with Reset
I installed the license and the problems began.
I determined that the G540 was not always seeing the charge pump causing it to issue a "Disable input" (E-Stop), so I disabled the feature on the G540.
Then I found that the PC was not always seeing the E-Stop status at the parallel port.
I measured voltages at the parallel port and found it was a 3.3 volt port with operating at 3.4-3.6v. Gecko specs say >3.3V is OK, so it should have been OK.
A scope showed significant (200mV) high frequency (115kHz) noise levels on the input and outputs of the G540. The signal was still present when all the i/o connections were removed and the PC powered off so I concluded that the noise was coming from within the G540. I sent the G540 back to Gecko but it was returned- No problem found.
I cleaned the hard disk, reinstalled WinXP and Mach3 (with no license) and all was well.
I installed the license and it all began again.
I still feel that the G540 was not performing to spec. My PC signals were clean and within spec but the "noise" apparently from the G540 was sufficient