One manifestation of this problem is that a BRAY will pass through a switch that is turned from OFF to ON the frame after the BRAY is fired (although, oddly, the BRAY's target is sparked at the same time as a BRAY with no FILTs/SWCHs; see example).

Here is an example of this behavior:

The left side has 16 different configurations of FILTs between an ARAY -> SWCH -> PSCN target. Follow the instructions in the save. Note that the bottom 8 (with a FILT adjacent to the ARAY) fire continuously when you hold the test button. Also note that, in the bottom 8, the BRAY spark makes it through the SWCH. See, too, that the timing of the destination spark is identical for both ARAYs, which is odd because the fact that the second ARAY fires through the SWCH implies that the spark is travelling one frame later than with an ARAY with no FILT (so I'd expect the spark to be at least one frame behind).

The right side simply shows the continuous sparking. Just hold the PSCN button to see. Removing the FILT adjacent to the ARAY fixes the problem. This example also shows that the problem does not require a SWCH to occur (it's just that I first noticed this when using a SWCH, and FILTs to cover the ARAY for decorations).

@jacksonmj: This problem also occurs in your test build 133. I have not tried it with the second spark test version that you posted yet. Also in build 133 pause before sparking test and step, observe the different timings of the bottom INST flashing in the failing cases on the left - the timings seem to be dependent on the FILT configuration.

-C

@cracker64: But why does the ARAY beam make it through a SWCH that is turned on in the same frame when there is a FILT adjacent to it, but not without a FILT?