Here's a function to avoid the issue (also allows a non-blocking msgbox).
It's an ugly version but I'm sure you guys will improve it
Func MsgBox_ext($type = 0, $title = "", $txt = "", $block = 1)
$txt = StringRegExpReplace($txt, "('|" & '")', "$1$1")
$type = StringRegExpReplace($type, "('|" & '")', "$1$1")
$title = StringRegExpReplace($title, "('|" & '")', "$1$1")
If $block <> 1 Then
Return Run(@AutoItExe & ' /AutoIt3ExecuteLine "' & "MsgBox('" & $type & "','" & $title & "','" & $txt & "')" & '"')
Else
Return RunWait(@AutoItExe & ' /AutoIt3ExecuteLine "' & "Exit(MsgBox('" & $type & "','" & $title & "','" & $txt & "'))" & '"')
EndIf
EndFunc ;==>MsgBox_ext