Homing To Index Following Error

I have a 4 axis router with step/dir servos using a 7i76EU+7i85 to command the servos and read the encoder feedback.  I have the servos reasonably tuned running closed loop.  But I'm seeing a following error spike on homing to index for the W axis (XYZW) on the first attempt at homing the machine after power up.  After the initial encoder position reset on the homing index it will home fine the 2nd try and works after that. If the machine was parked at the W-zero location when Linuxcnc is turned off and started it does not do the following error.  For some reason it seems like Linuxcnc is not ignoring the F-eror on the encoder index reset for the W-axis like it should.  Any Ideas how to fix this?

Here are my main hal and ini config files.
 

Here's a Halscope shot of it.
 

Here's another Halshow screen shot showing the index input.