Watching with interest. I had similar weird "double hits" on the "1" on the MODX after doing an "undo" in either MIDI or Pattern Recorder.

It was suggested that this was caused by playing "too early" before the first beat of the next Measure beyond the Loop or End point. As such this "played too early" keystroke was appearing at the very end of Beat 4, before the loop/end point but sounding like it was played on Beat 1.

The advised workaround was either A) Don't make any mistakes forcing an Undo and Re-Record or B) Do not play any keys after Beat 4 of the last Measure. Option B took some musical skill counting through the Measures, but if done correctly... there was no double note (overdub) on Beat 1.

I read somewhere (maybe here) that the Recorders on the Montage/MODX were inherited from the MOTIF/MOXF. So, this post did catch my attention.

In your case, Copy Event implies some manipulation/editing of the base data file. I would imagine Undo/Redo also involves some data manipulation (as opposed to starting with a fresh blank/empty file).

I am not saying there is, or could be any link between MOXF and MODX, but I would be interested in seeing the outcome.

After doing a COPY EVENT of one or several measures, I find that a snare hit on the 1 count has been added to the Event List. This is not a phantom hit (4:479) from the previous measure. It's a brand new perfect 1:000 event on the incoming measure. I've noticed it mostly with a drum sequence edit it's always a snare hit!

It is likely that the COPY EVENT dialog box was improperly filled in. In order to help you we would need to know exactly what you filled in.

COPY EVENT - "one or several measures" unfortunately is really not specific enough. Perhaps this will help
Say you want to COPY the EVENTS in TR1 Measure 1 to Measure 5

TR01 ___ 001:1:000 -- 002:1:000
- - - - - - - TO - - - - - -
TR01 ___ 005:1:000
NumberOfTimes x01

Please recount how you setup the dialog box and what it is exactly that you wanted to accomplish.
Also press [EDIT] on the Track and tell us what NOTE that "perfect 1:000 event" is _ that is important information.

One or several was just to indicate that I've had it happen in various scenarios, but the COPY EVENT would be straight forward, as in your example. Nothing hanging over. In fact, if I wanted to include the pickup notes from the previous measure that's when it would NOT occur. It's when it's a straight 1-4.000 replace operation that's when the ghostly snare hit event would be added on the 1.000 of the first measure being COPIED.

I'll do some more COPY EVENT operations and wait for it to happen. Then I'll get back with more details.