I have often used this form of the wrapfigure, but I notice that sometimes I have this problem.
\documentclass[pdftex,10pt,a4paper]{book}
\setlength{\oddsidemargin}{0 mm}
\setlength{\topmargin}{0 mm}
%\setlength{\headheight}{7 mm} %latezza capotesta
%\setlength{\headsep}{9 mm}
\setlength{\evensidemargin}{0 mm}
\setlength{\marginparwidth}{0 mm} %% per le note a bordo?
\setlength{\textheight}{230mm} %Altezza Testo
\setlength{\textwidth}{150mm}
\usepackage[demo]{graphicx}
\usepackage{wrapfig}
\usepackage{mwe}
\usepackage{caption}
\usepackage{lipsum}
\begin{document}
\lipsum[1-1]
\begin{wrapfigure}[11]{l}[\dimexpr \marginparwidth]{5.5cm}
\centering\raisebox{\dimexpr \topskip-\height}{%
\includegraphics[width=5.0cm]{example-image-a}}
\captionof{figure}{Titolo dell'immagine casuale}
\end{wrapfigure}\hfil
\lipsum[2-3]
\begin{wrapfigure}[11]{r}[\dimexpr \marginparwidth]{5.5cm}
\centering\raisebox{\dimexpr \topskip-\height}{%
\includegraphics[width=5.0cm]{example-image-a}}
\captionof{figure}{Titolo dell'immagine casuale}
\end{wrapfigure}\hfil
\lipsum[4-5]
\end{document}
any suggestions on this?