That's difficult to swallow.

Further research into the so-called "ghost-note" issue has revealed that it is extrememly unlikely that these discordant notes are ghost notes modeled from the amplifiers.

There are at least a dozen amplifier models in the POD X3 and Spider IV amplifier (and probably many more products) exhibiting this problem, and the suspicious fact that makes it difficult to believe these are modeled after the amplifier itself, is that every one of these models exhibits the exact same discordant note. One would expect each amplifier that was being modeled would exhibit its own unique-sounding artifact, yet this is NOT the case with these modeled amplifiers.

Have a listen for yourself and come to the only logical conclusion available.

PS. I have not yet listened to the POD HD, but I will report back what I find in this regard.