Homing Offset Continues Indefinitely

I'm building my first CNC machine and am at the point of configuring Mach3 and testing everything out. For the most part everything works as expected except for one strange problem I am having with trying to Home the Y axis. I am using the combined limit/home switch method, so the limit switches on each axis double as the homing switch. What happens is that when the Y axis homes, it moves at the slower speed until it hits the homing switch, then it reverses at an even slower speed to come off the switch like it should-- but it never stops! It will travel all the way across the gantry to the other side and hit the opposing limit switch, except this time the machine does not shut down the way it normally would since it is in the Home mode and is ignoring the input from limit switches. No amount of manually clicking the limit switches will stop it, so you have to ESC to kill it. It seems like the software is trying to implement the home offset value but just never stops. It is as if it is interpreting the offset as some huge value or never sees the switch close again after it is hit. I've tried setting the offset value to zero in the Home/Limits settings but it has no effect. All limit switches are working and normally shut the system down when jogging in the normal operating mode. Y axis has been calibrated accurately in the motor tuning section and moves the proper distances when sent G codes. The X axis motors home normally and do not have this problem. The problem occurs both when all motors are homed using Ref All Home or each is homed individually in the diagnostics page. The switch debounce time is set to 1000 and I have tried zero and 3000 as well. All limit switches are the same switch model and test correctly on the diagnostics page.

I have provided some system info and screen shots of the relevant Mach screens below. This machine is a fabric cutter with the X axis slaved to a B axis, with the A motor being used for a tangential cutting head. There is no Z axis, so the homing process begins with the Y axis when using the Ref All Home button. The A motor is setup to be angular, and when that one homes it trips a limit reset when the home switch is hit which the others do not do, so it is not quite working right either.

System Specs:
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Mach3, version 2 R3.043.062
Windows 8 running on laptop
Smooth Stepper (ethernet verison) plugged into a C10 breakout board
NC limit switches wired in series as pairs (-X +X on 1st input line, -Y +Y on 2nd input line etc.)
KL-4030 drivers from Keling set to 1/4 microsteps

Attached Images

• startup_screen.jpg‎ (157.3 KB)
• home_settings.jpg‎ (100.6 KB)
• motor_settings.jpg‎ (109.8 KB)