I'm having a helluva time figuring out how to edit/mask one of my
memory channels on my VX-7R.

The really odd thing is, I can edit or mask *any* other memory channel,
except for this particular one!

I'm not using any memory groups, "special", nor one-touch memories.
Just the basic bank of 499 (or whatever).

Steps I take to edit the memories:

* V/M toggle to VFO mode
* Select freq. & tone settings
* MON/F for .5 secs
* Dial to desired memory number
* MON/F

This works on *any* other memory channel (even existing ones), except
#7. I can't mask it, either.
What is happening? How can I edit this memory channel?

Thanks.