@sladflob: c.f.,
this post in particular.
Sidebar: I'd recommend not sticking with an old version (of anything, really

). But, in this case: there have been subtle changes to the FW that required code tweaks in KFMon to ensure consistent behavior.
@perisiana: I'm repeating this, mostly for future readers: do note that the new setting we've just been discussing achieves the very same thing (preventing Nickel from picking up KOReader's icons, among other things) without having to monkey-patch Nickel

.
(i.e., unless you have a specific need for the preload approach, I'd recommend new users stick with the setting. Which is why that's what the install script uses

).