\RequirePackage{atbegshi}
\let\oldlabel\label
\documentclass{beamer}

\usetheme{Marburg}
\usepackage[transparent,minimouseover,fixcolor
]{ocgtools}

\AtBeginDocument{\let\label\oldlabel}
%\usepackage{helvet}

\input ocgtools-test.tex

\end{document}