Based on the fact:
- you said "Don't show unique icons" works around the issue completely, thereby providing a workaround;
- "Don't show unique icons" works around an issue in Windows itself, thereby pointing to the issue being of third-party cause; and
- rebooting also works around the problem (inconvenient perhaps but means you can still use C2)
then this seems to have a relatively minor impact and points to a third-party issue beyond our control, which also appears to be infeasible to work around further at this point (since we have already worked around it with "Don't show unique icons" mode).
Posting pages of arguments is also by far the biggest discouragement possible to investigating what appears to be a third-party bug. We sometimes go above and beyond the call of duty and try to fix/work around them anyway, to provide the best possible support for users. However arguing over this on the forums is a very effective way to make me think it's just a waste of my time and just leave it to the third party. If you want the best chance possible that this is actually investigated and worked on, don't do that.
As I said in my second post, I don't believe there's anything further we can reasonably do about this. I'm basically leaving this issue open as a known issue, but if there is any more trolling over blame or explanation or unreasonable support expectations, I will close it right away. Like I said, if you think this is unreasonable, go and use other software, where you will doubtless run in to similar issues or worse.