Modded Flashback 2 screen clarity?

I bought a modded FB2 a few months ago.  Whenever I load games I see some ghost-like artifacts like I see when using the old RF cable.
Is this normal for a modded FB2?  Nothing out of the ordinary that I would see on an unmodded 2600, but I ask because my unmodded system does not do this.

Best regards,
Tremoloman