Acronym package: printonlyreused and capitalizing doesn't work

The recent version of the acronym package provides options to only print multiply used acronyms ([printonlyreused]) to the list of acronyms as well as capitalizing e.g. long versions (Acl{XYZ}).
Capitalizing worked for me in an earlier version.
I updated the package to version 1.46 but none of the above mentioned works now.
I also re-installed the required packages suffix and xstring.
I’m using MiKTeX 2.9.7380 with PDFlatex and also reset MiKTeX configuration but nothing helped.

Please find below a MWE to describe the problem. In my output, the long version of A is not capitalized, and B is still on the list.

documentclass[12pt]{article}
usepackage[printonlyreused]{acronym}
begin{document}

section{Chapter}
First use: ac{NA}  
2nd use: ac{NA}   
Long version with capital: Acl{NA} 
Other acronym, only mentioned once: ac{NB} 
The third acro is not mentioned to be excluded on the printed list

section{List of acronyms}
begin{acronym}
acro{NA}{new acro A}
acro{NB}{new acro B} % negative test for [printonlyreused]
acro{NC}{new acro C} % negative test for [printonlyused]
end{acronym}

end{document}

As a workaround I switched to package acro, luckily it uses mostly the same in-text commands so I didn’t have to change much in my 130 pages document, only redefining >4 pages of acronyms was somewhat tedious. However, a solution using acronym would still be useful.