At the very least this should be documented. Will someone take on either A) adding the documentation or B) updating Counter to look for the last period to determine the extension (instead of the first period, which is probably what it's doing now though I haven't confirmed this).
I don't notice anything unusual with the code (Counter.cpp).
If it uses the CMeta::Deextension() to get the extension of the filename, this method should correctly find the extension, as it looks for the first period in the reverse direction.
From what I've noticed, Counter.cpp seems to be using CMeta::Deextension() consistently throughout.
It would be good for peak to provide usage cases for duplicating the problem.